DOC: move and reword whatsnew note for replace fix (GH-57865)

[jorisvandenbossche]

We ended up backporting #57865 after it was already merged, so also moving the whatsnew note here (and I also reworded it slightly, because AFAIK it's not limited to regex cases, given the example in #61948)

[lumberbot-app]

Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

git checkout 2.3.x
git pull

2. Cherry pick the first parent branch of the this PR on top of the older branch:

git cherry-pick -x -m1 7252e9f338f44d6f1e1464171953eb69b7114be2

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

git commit -am 'Backport PR #62153: DOC: move and reword whatsnew note for replace fix (GH-57865)'

4. Push to a named branch:

git push YOURFORK 2.3.x:auto-backport-of-pr-62153-on-2.3.x

5. Create a PR against branch 2.3.x, I would have named this PR:

"Backport PR #62153 on branch 2.3.x (DOC: move and reword whatsnew note for replace fix (GH-57865))"

And apply the correct labels and milestones.

Congratulations — you did some good work! Hopefully your backport PR will be tested by the continuous integration and merged soon!

Remember to remove the Still Needs Manual Backport label once the PR gets merged.

If these instructions are inaccurate, feel free to suggest an improvement.

[jorisvandenbossche]

Backport -> #62156