[3.13] gh-69686: Remove untrue part of `__import__` replacement docs (GH-143261) (#143282)

gh-69686: Remove untrue part of `__import__` replacement docs (GH-143261)

Remove untrue part of `__import__` replacement docs

The original statement effectively says that replacing `__import__` at global scope affects import statements, and not only that, but only import statements within the rest of the executing module. None of that has been true since at least Python 2.7, I think.

This was likely missed in python/cpython#69686.
(cherry picked from commit 79c03ac0015ccf1cbb759f870e2af9d68f60fe3a)

Co-authored-by: Thanos <111999343+Sachaa-Thanasius@users.noreply.github.com>