feat: use golangci-lint for code static analysis

[Dreamacro]

As described in #775, boxo requires a better static code analysis tool since the currently used ipdxco/unified-github-workflows has limitation capabilities.

Therefore, I am attempting to use golangci-lint here (while retaining the original ipdxco/unified-github-workflows). I have disabled all golangci-lint default configurations and enabled some checks that I find particularly valuable.

After performing the lint fixes, boxo generally has the following issues:

1. Some files have imported package names divided into groups without any discernible pattern (if there is one, please let me know), and gci can fix this.
   for example:
   

   boxo/ipld/unixfs/io/dagreader_test.go

   Lines 3 to 15 in 8ca0ca2

   	import (
   	"bytes"
   	"io"
   	"strings"
   	"testing"
   	mdag "github.com/ipfs/boxo/ipld/merkledag"
   	"github.com/ipfs/boxo/ipld/unixfs"
   	context "context"
   	testu "github.com/ipfs/boxo/ipld/unixfs/test"
   	)

2. many unnecessary type conversions can be detected and fixed using unconvert.
3. Other minor issues, such as unnecessary blank lines, octal notation, statements that will never be executed, etc.

There might be some other valuable plugins, such as unused, and I would like to hear your opinions on them.

[codecov]

Codecov Report

Attention: Patch coverage is 74.19355% with 8 lines in your changes missing coverage. Please review.

Project coverage is 60.54%. Comparing base (8ca0ca2) to head (528dbb8).

Files with missing lines	Patch %	Lines
gateway/serve_http_content.go	25.00%	1 Missing and 2 partials ⚠️
files/util.go	66.66%	1 Missing ⚠️
filestore/fsrefstore.go	0.00%	1 Missing ⚠️
gateway/backend_car_files.go	0.00%	1 Missing ⚠️
ipld/unixfs/unixfs.go	0.00%	1 Missing ⚠️
routing/http/types/json/responses.go	50.00%	1 Missing ⚠️

@@            Coverage Diff             @@
##             main     #797      +/-   ##
==========================================
+ Coverage   60.51%   60.54%   +0.02%     
==========================================
  Files         245      245              
  Lines       31132    31131       -1     
==========================================
+ Hits        18840    18847       +7     
+ Misses      10615    10611       -4     
+ Partials     1677     1673       -4     

Files with missing lines	Coverage Δ
bitswap/bitswap.go	69.13% <ø> (ø)
bitswap/client/internal/getter/getter.go	81.81% <ø> (ø)
bitswap/client/internal/peermanager/peermanager.go	91.85% <ø> (ø)
...wap/client/internal/peermanager/peerwantmanager.go	88.50% <ø> (-0.04%)	⬇️
...tswap/client/internal/session/sessionwantsender.go	97.65% <ø> (+0.70%)	⬆️
...l/sessioninterestmanager/sessioninterestmanager.go	100.00% <ø> (ø)
...p/client/internal/sessionmanager/sessionmanager.go	100.00% <ø> (ø)
.../internal/sessionpeermanager/sessionpeermanager.go	100.00% <ø> (ø)
bitswap/client/wantlist/wantlist.go	90.62% <ø> (ø)
bitswap/message/message.go	83.87% <100.00%> (ø)
... and 62 more

... and 5 files with indirect coverage changes