I think it might be better to let the pre-commit updates accumulate here until right before we start working on a PR. When there's multiple, they get lumped into the same PR, and we only have to merge once.

I disagree. These updates are scheduled monthly (instead of weekly), and the PRs ensure that at least one of us reviews the codebase and keeps it current with changes in C, C++, and Python, as well as the pre-commit tools.
That is completely separate from when we choose to make a new release to PyPI.

the PRs ensure that at least one of us reviews the codebase and keeps it current with changes in C, C++, and Python

I don't think that is true. Nothing pre-commit does makes us support any more of C/C++, nor follow new releases of Python unless we change our policy for bumping the required Python version.

It's not making us make changes to update it so, either. The bugs about language support still stay there and such PRs seldom appear due to autoupdate PRs. Deciding to merge this PR has no advantage over setting a personal monthly timer. Plus, new changes being added to a PR monthly still generates the same notifications.