Upgrades dependencies and fix generated bindings

[sitatec]

Fix #234
Upgraded ffigen to 12.0.0 ffi to 2.1.3 and melos to 6.1.0. Upgraded melos due to dependencies conflicts.
ffigen 13.0.0 is the latest, but the generated bindings produced a lot of errors that requires deep understanding of the lib to fix safely.
Also, Since 11.0.0:

Any compiler errors/warnings in source header files will now result in bindings to not be generated by default, since it may result in invalid bindings if the compiler makes a wrong guess. A flag --ignore-source-errors (or yaml config ignore-source-errors: true) must be passed to change this behaviour.

I was getting this error before and after upgrading, so I bypassed it with --ignore-source-errors:

[SEVERE] : Header ./src/tensorflow_lite/metal_delegate.h: Total errors/warnings: 2.
[SEVERE] :     ./src/tensorflow_lite/metal_delegate.h:81:49: error: unknown type name 'id' [Semantic Issue]
[SEVERE] :     ./src/tensorflow_lite/metal_delegate.h:81:51: error: expected ')' [Parse Issue]

I don't know if this error is specific to me because I don't have Metal libs installed, but it wasn't caused by the upgrade. Beside, the library tests are passing, and I tested it with my app, it is also working as expected.

[PaulTR]

Closing since another PR handles similar issue - this one modifies a generated class that would get overwritten at publish.