fix(rl): robust integer validation for utils.py (Fixes #953)

[abdulwahabahmedkhanyusufzai]

This PR fixes an AttributeError crash encountered when using is_positive_integer with Numpy types (e.g., np.int64) or on Python 3.11+ where certain types lack the .is_integer() method.

This supersedes stale PRs #903 and #930. I have consolidated the fix and added the missing unit tests requested by maintainers.

Changes:

Implemented a safe is_integer_value helper that handles int, float, and numpy types correctly.

Added tests/rl/rl_utils_test.py to verify the fix across all types.

Related Issues:

Fixes #953

Resolves #903

Resolves #902

Test Plan
Created a new test file tests/rl/rl_utils_test.py. Verified locally with python3 -m unittest tests/rl/rl_utils_test.py.

Results:

✅ int (Standard) - Passed

✅ np.int64 (Numpy) - Passed (Previously crashed)

✅ float (Standard) - Passed

✅ bool - Rejected correctly

[abdulwahabahmedkhanyusufzai]

Hi @abheesht17. This PR resolves the AttributeError in is_positive_integer which is currently breaking compatibility for Python 3.11+ and NumPy users (Fixes #953).

I've consolidated the previous work from #903 and #930 and added full unit tests. Could you please approve the workflows so the CI can verify the fix? Thanks!

[cats256]

Just a note for maintainers, AI-generated pull requests (code + responses) with a clear lack of efforts have become a very prevalent issue with PyTorch and it appears this has spread to other open-source projects