Formally mark deprecated items in threading for removal in 3.21

Feature or enhancement

Proposal:

Several camelCase names in the threading module have been marked with DeprecationWarnings since 3.10. (they are replaced by snake_case names and in some cases with properties rather than getter/setter functions) However, they have never had a removal version set.

I propose to mark these for removal in 3.21 and will prepare a PR to do so.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-154206

まず threading モジュールに既存する DeprecationWarnings と、関連する PR gh-154206 を確認します。削除バージョンが指定されていない camelCase 名を特定します。関連する非推奨項目で一貫して Python 3.21 での削除が示されれば完了です。