_typing: Redirect more typing classes and hide _typing from doc gen

[bkeryan]

• This contribution adheres to CONTRIBUTING.md.

What does this Pull Request accomplish?

Add redirection/stubs for more of the standard typing module.

Hide _typing.py from documentation generation by importing it as a fallback for ImportError:

try:
    from typing import TypeAlias
except ImportError:
    from nitypes._typing import TypeAlias

As far as the doc tools are concerned, we're using the standard Python typing module directly.

Update check_docs.yml to use Python 3.13.3, for the latest typing module.

Why should this Pull Request be merged?

Stop thinking about _typing

What testing has been done?

poetry run nps lint, mypy, pytest -v
Generated docs and inspected type aliases.

[github-actions]

Test Results

0 files   -    10  0 suites   - 10   0s ⏱️ -24s
0 tests  -   511  0 ✅  -   511  0 💤 ±0  0 ❌ ±0 
0 runs   - 5 110  0 ✅  - 5 110  0 💤 ±0  0 ❌ ±0 

Results for commit 7148b85. ± Comparison against base commit 10bdfbe.

♻️ This comment has been updated with latest results.

[bkeryan]

docs before:

docs after:

[bkeryan]

Hide _typing.py from documentation generation by importing it as a fallback for ImportError:

try:
    from typing import TypeAlias
except ImportError:
    from nitypes._typing import TypeAlias

This fixes the documentation generation but it breaks mypy due to https://www.github.com/python/mypy/issues/14220