[Python] Type checking in CI

[dbrattli]

Testing out reporting type annotation errors in the generated Python library and test code, so we can keep the number under control and know if a PR reduces the number of type errors in the generated code or not.

• The GH action will comment on the PR, but not fail the build (for now).
• Will only trigger if Python related files are touched:

- 'src/Fable.Transforms/Python/**'
- 'src/fable-library-py/**'
- 'tests/Python/**'
- 'pyrightconfig.ci.json'
- 'pyproject.toml'

[github-actions]

Python Type Checking (Pyright) Results

✅ All non-excluded files pass

Metric	Value
Excluded files	6

Files excluded from type checking

These files have known type errors and are excluded from CI. Remove from pyrightconfig.ci.json as errors are fixed.

temp/fable-library-py/fable_library/list.py
temp/tests/Python/fable_modules/thoth_json_python/encode.py
temp/tests/Python/test_applicative.py
temp/tests/Python/test_map.py
temp/tests/Python/test_misc.py
temp/tests/Python/test_type.py