contrib: Ignore the r14-5312-g040e5b0edbca861196d9e2ea2af5e805769c8d5d bogus commit

The r14-5312-g040e5b0edbca861196d9e2ea2af5e805769c8d5d commit log contains
a line from git revert with correct hash, but unfortunately hand ammended
with explanation, so it got through the pre-commit hook but failed during
update_version_git generation.  Please don't do this.

2023-11-14  Jakub Jelinek  <jakub@redhat.com>

contrib/ChangeLog:
	* gcc-changelog/git_update_version.py: Add
	040e5b0e to ignored commits.