Fix trivial mypy errors

[bizfsc]

Fix trivial mypy errors to prepare for type checking adoption.

Changes

pyproject.toml

• Add [[tool.mypy.overrides]] to ignore missing imports for can and canmatrix (third-party libraries without type stubs).

canopen/objectdictionary/__init__.py

• Replace List[int] with list[int] (PEP 585, supported since Python 3.9).
• Add type annotations for subindices and names dicts in ODRecord and ODArray.

canopen/lss.py

• Annotate self.responses as queue.Queue[bytes].

canopen/node/local.py

• Annotate _read_callbacks and _write_callbacks as list[Callable].

canopen/node/remote.py

• Annotate sdo_channels as list[SdoClient].

Impact

Reduces mypy errors from 95 to 87 (eliminates all import-not-found, name-defined, and var-annotated errors).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[acolomb]

Do the two libraries really not ship any typing info? At least for python-can, I'm certain they do have them, but not as stubs.

Oh, and please, could we try to separate a bit more, touching only related modules at a time?

[bizfsc]

Oh, and please, could we try to separate a bit more, touching only related modules at a time?

I though about this, but I decided against it, because I really tried only to fix the most trivial cases in this PR. There will be future PRs (currently working on it) which will be separated by mypy topic.
Per module PRs are not applicable here, then we would have Count of PR = topic * module. Putting together different topics but for one module in a single PR also seems bad.
The structure of the changes in this PR are coherent and straight forward to review, don't you think?

[acolomb]

Alright, it is in fact fairly straightforward. One more thing I'd stuff in there though is annotating the argument of add_read_callback() and add_write_callback(), since their only purpose is writing to the newly types lists.

What about the dependency typing info? canmatrix has it in the development branch, but not yet released. can is properly typed and marked as such.