Fix Type hint

[ZhipengXue97]

Description

Fix Several type check warnings reported by Pyre@Google, which were outdated after code modifications.

Detail

1. update the return type of function color_to_triple from tuple[int, int, int] to Union[list, tuple[int, int, int]], according to the condition check, color could be list and directly return after commit 3613061
2. update the return type of function build_dataset from tuple[DataLoader, DataLoader, DataLoader] to tuple[DataLoader, DataLoader, DataLoader | None], the test_dl is init as None and could directly return if self.test_ds is None after commit d193109
3. update the return type of function validate_augmentors from str to list[str], the input v is list[str] and directly return after condition check after commit adac1a2
4. update the return type of function _build_dataset from tuple[Dataset, Dataset, Dataset] to Dataset, since the function only returns a Dataset after commit d193109
5. update the return type of function _build_dataset from tuple[Dataset, Dataset, Dataset] to Dataset, since the function only returns a Dataset after commit d193109

[AdeelH]

Thank you very much for the PR! We require contributors to sign a CLA before their changes can be accepted. See instructions here: https://docs.rastervision.io/en/stable/CONTRIBUTING.html#contributor-license-agreement-cla. Let me know when you've submitted it.

[ZhipengXue97]

Hi, @AdeelH, I have signed and submitted the CLA.

[AdeelH]

The CI failure looks to be formatting-related. You will need to run scripts/format_code and scripts/style_tests using the versions of flake8 and yapf in requirements-dev.txt.

[AdeelH]

Thanks!

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.15%. Comparing base (9f7237d) to head (e9e98c4).
Report is 41 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2195      +/-   ##
==========================================
- Coverage   90.22%   90.15%   -0.07%     
==========================================
  Files         198      198              
  Lines        9888     9888              
==========================================
- Hits         8921     8915       -6     
- Misses        967      973       +6     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.