Not skipping all dot directories

[AryazE]

Describe the bug

In this loop, if there are at least 2 directories that start with . and are adjacent in the dirnames list, then one of the is not skipped. This happens because the dirnames.remove(dirname) changes the list it is iterating on.

How to Reproduce

Just having two directories like .dotdir1 and .dotdir2 should trigger this problem.

Environment Information

Platform:              linux; (Linux-5.19.0-46-generic-x86_64-with-glibc2.35)
Python version:        3.10.12 (main, Jun 11 2023, 05:26:28) [GCC 11.4.0])
Python implementation: CPython
Sphinx version:        7.2.5
Docutils version:      0.20.1
Jinja2 version:        3.1.2
Pygments version:      2.16.1

Sphinx extensions

No response

Additional context

No response