[duriantaco]

Summary

Hi! This is a cleanup.

• Removed _DICT_FIELDS and _NOT_FOUND from metadata.py, nothing references them (the other field sets are still used)
• No behaviour changes and no changes made to any APIs

Found with Skylos, a deterministic tool. No AI was used in this PR.

[henryiii]

Did a quick history check, below.

🤖 AI text below 🤖

Both came in with 61e6efb, "Support enriched metadata in packaging.metadata" (#686, Brett Cannon, 2023-08-18).

• _DICT_FIELDS was used at first. The _Validator.__get__ fallback used it to return {} when project_urls was missing, and a test (test_dict_default) was parametrized on it. Commit 09f131b, "Default optional metadata values to None" (#734, 2023-10-15), changed the fallback to instance._raw.get(self.name) and removed that test. Since then nothing has used it.
• _NOT_FOUND was never used. The only reference in 61e6efb is its definition. It is most likely left over from an earlier draft of that PR.

[henryiii]

Out of curiosity, I ran vulture and processed it's output with AI (due to the large number of false positives), and this is what made it through:

🤖 AI text below 🤖

• tests/property/test_version_releases.py:84-126: PRE_POOL, POST_POOL, DEV_POOL and EPOCH_POOL are defined but never used. Only FINAL_POOL is used, at line 223. They came in with Add property-based tests for PEP 440 #1144, which added the PEP 440 property tests, so they are probably leftovers or pools that were meant for later tests.
• src/packaging/version.py:76: the alias VersionComparisonMethod is not referenced anywhere in the repo.

[duriantaco]

Thanks for checking the history and merging this! Greatly appreciate the extra findings also