mock.patch introspects original even when new_callable set

[rbtcollins]

Bug report

Bug description:

In order to patch flask.g e.g. as in #84982, that proxies getattr must not be invoked. For that, mock must not try to read from the original object. In some cases that is unavoidable, e.g. when doing autospec. However, patch("flask.g", new_callable=MagicMock) should be entirely safe.

CPython versions tested on:

3.11, 3.12

Operating systems tested on:

Linux, macOS, Windows, Other

Linked PRs

• gh-119600: mock: do not access attributes of original when … …new_callable is set #119601
• [3.13] gh-119600: mock: do not access attributes of original when new_callable is set (GH-119601) #120334
• [3.12] gh-119600: mock: do not access attributes of original when new_callable is set (GH-119601) #120335