Skip PR message reminder check for all-contributors bot

[tlylt]

Please confirm that you have searched existing issues in the repo

Yes, I have searched the existing issues

Any related issues?

No response

Tell us about your environment

Windows 10

MarkBind version

Master branch

Describe the bug and the steps to reproduce it

The CI will fail for the auto generated PR by all-contributor bot due to no proposed commit message:

• https://github.com/MarkBind/markbind/actions/runs/9772207866/job/26976229640?pr=2560

Expected behavior

Fix CI failure by skipping the check if the PR author is the all-contributor bot (or any bot if possible, since other bots might have the same issue).

Anything else?

No response