Bump Elixir and Erlang versions used for development

[takasehideki]

In this PR, I'd like to suggest that Elixir and Erlang versions shall be bumped for development.
These are implicitly specified in .tool-version.

• Elixir: 1.15.7-otp-26 -> 1.17.3-otp-27
• Erlang/OTP: 26.1.2 -> 27.1.2

These are the latest versions that can be installed asdf at this time. Of course, keeping them fresh is preferable, but I think reviewing them at the proper timing is sufficient.

Also, I have added these version numbers (along with Rust) clearly in README.

[takasehideki]

During mix compile, toml caused the following warning.

==> toml
Compiling 10 files (.ex)
     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 264 │   defp handle_token(lexer, original, doc, type, skip, _data, lines) when type in '-_' do
     │                                                                                  ~
     │
     └─ lib/decoder.ex:264:82

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 371 │       {:ok, {type, _skip, _data, _lines}} when type in '-+' ->
     │                                                        ~
     │
     └─ lib/decoder.ex:371:56

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 419 │           {:ok, {:alpha, _, <<c::utf8>>, _}} when c in 'eE' ->
     │                                                        ~
     │
     └─ lib/decoder.ex:419:56

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 474 │       {:ok, {:alpha, _, <<c::utf8>>, _}} when c in 'eE' ->
     │                                                    ~
     │
     └─ lib/decoder.ex:474:52

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 514 │       {:ok, {sign, _, _, _}} when sign in '-+' and last == ?e ->
     │                                           ~
     │
     └─ lib/decoder.ex:514:43

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 518 │       {:ok, {:alpha, _, <<c::utf8>>, _}} when c in 'eE' and signal == ?. ->
     │                                                    ~
     │
     └─ lib/decoder.ex:518:52

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 522 │       {:ok, {?_, skip, _, lines}} when last not in '_e.' ->
     │                                                    ~
     │
     └─ lib/decoder.ex:522:52

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 538 │       {:ok, {type, skip, data, lines}} when last in 'e.' ->
     │                                                     ~
     │
     └─ lib/decoder.ex:538:53

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 542 │       {:ok, {_type, skip, _data, lines} = token} when last not in '_e.' ->
     │                                                                   ~
     │
     └─ lib/decoder.ex:542:67

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 682 │         {:ok, {sign, _, _, _}} when sign in '-+' ->
     │                                             ~
     │
     └─ lib/decoder.ex:682:45

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 796 │       {:ok, {sign, _, _, _}} when sign in '-+' ->
     │                                           ~
     │
     └─ lib/decoder.ex:796:43

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 916 │         {:ok, {type, skip, _, lines}} when type in '-_' ->
     │                                                    ~
     │
     └─ lib/decoder.ex:916:52

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 954 │               {:ok, {type, _, _, _}} when type in '-_' ->
     │                                                   ~
     │
     └─ lib/decoder.ex:954:51

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 969 │       {:ok, {type, _, _, _}} when type in '-_' ->
     │                                           ~
     │
     └─ lib/decoder.ex:969:43

     warning: single-quoted strings represent charlists. Use ~c"" if you indeed want a charlist or use "" instead
     │
 983 │           {:ok, {type, _, _, _}} when type in '-_' ->
     │                                               ~
     │
     └─ lib/decoder.ex:983:47

Generated toml app

This has already been suggested and fixed in bitwalker/toml-elixir#40 . However, toml-elixir development seems to have stalled for 2 years,,,
In conclusion, we can ignore this warning.

[takasehideki]

mix test caused the following warning (and failed in GHA CI because of using the --warnings-as-errors).

Running ExUnit with seed: 520576, max_cases: 20

warning: pattern matching on 0.0 is equivalent to matching only on +0.0 from Erlang/OTP 27+. Instead you must match on +0.0 or -0.0
└─ test/zenohex/nif_test.exs: Zenohex.NifTest."test subscriber subscriber_recv_timeout/1"/1

...............................................................
Finished in 27.0 seconds (0.00s async, 27.0s sync)
19 doctests, 44 tests, 0 failures

The reason is the below. From Erlang/OTP 27+, it is now recommended to explicitly write +0.0 or -0.0 (since these floating point values are internally different).
https://erlangforums.com/t/in-erlang-otp-27-0-0-will-no-longer-be-exactly-equal-to-0-0/2586

So I added b45426f to fix this.
Also, I have already checked that this change does not affect mix test with the previous version (Elixir 1.15.7-otp-26 and Erlang/OTP 26.1.2).

[takasehideki]

Umm,,, mix test --cover failed,,, Coverage is clearly declining, for example Zenohex.Config is at 0%.
https://github.com/biyooon-ex/zenohex/actions/runs/11697005860/job/32575217597
https://github.com/biyooon-ex/zenohex/actions/runs/11677169096/job/32514623108

@pojiro Do you know what happened??

[takasehideki]

Is this the information we should focus on??
https://elixirforum.com/t/elixir-v1-17-0-released/64151/2
elixir-lang/elixir#13761

[pojiro]

@takasehideki

Umm,,, mix test --cover failed,,, Coverage is clearly declining, for example Zenohex.Config is at 0%.

I also think elixir-lang/elixir#13761 causes this.
We can work around this by decrease the threshold value until the release of Elixir version which includes the fix.

[takasehideki]

@pojiro You are right!! I confirmed mix test with asdf install elixir main (its commit/fix has been taken) worked fine. We expect this will probably be taken in Elixir v1.7.4.
For now, I decided that we will change the threshold setting and leave the Issue as a reminder.

[takasehideki]

CI finally worked fine!! 🎉
Added memo to #77

[takasehideki]

@s-hosoai @pojiro could you give me your comments and/or reviews about my suggestion; bump Elixir to 1.17.3-otp-27 and Erlang/OTP 27.1.2 for development use.

[pojiro]

@takasehideki LGTM

[takasehideki]

OK, going to merge!
@s-hosoai feel free to let me know if you have any concerns.