Prevent templates autobumper from failing if dependencies don't change [skip ci]

[theopnv]

Purpose of this PR

Fix #1622 when the dependencies version is the same.

Prior to this PR, executing this job with dependencies version unchanged made it fail. It was because we edited the file and started the git pipeline no matter what, even if the dependencies did not change.

From now on we edit/commit/push the files only if the dependencies actually changed.

---

Testing status

Manual Tests: What did you do?

Automated Tests: What did you setup? (Add a screenshot or the reference image of the test please)

https://yamato.prd.cds.internal.unity3d.com/jobs/902-Graphics/tree/yamato%252Ffix-templates-auto-bump-2/.yamato%252F_preview_publish.yml%2523auto-version

There are 3 tests on this branch:

1. The older one is a mistake on my behalf, don't mind it (job was canceled)
2. The next one was to test the behavior when the dependencies were not updated: The job succeeds and no commit is made
3. The most recent one was to test the behavior when the dependencies were updated (basically confirming that the fix did not break the initial feature): The job succeeds and this commit was made: df32963

[theopnv]

Note: backport of this should be grouped with backports of #1622.