[Hermetic Build] The update config action doesn't work if the existing config update PR has merge conflicts

[diegomarquezp]

googleapis/java-pubsublite#1879 was not being updated for several days:

This is because googleapis/java-pubsublite#1879 had merge conflicts

In this cycle, I have observed this in 5 repositories including this one

[diegomarquezp]

cc: @blakeli0

[diegomarquezp]

We know that update_generation_config addresses "stale branch" problems by merging main, but we may need to do a git reset --hard origin/main or something of the likes.

sdk-platform-java/.github/scripts/update_googleapis_commit.sh

Lines 71 to 73 in 9cae675

	# Only allow fast-forward merging; exit with non-zero result if there's merging
	# conflict.
	git merge -m "chore: merge ${base_branch} into ${current_branch}" "${base_branch}"

[lqiu96]

@diegomarquezp is this still an issue? I believe the latest runs are successful: https://github.com/googleapis/java-pubsublite/actions/workflows/update_generation_config.yaml

[diegomarquezp]

I think this will only occur as long as there are merge conflicts in with the base branch. Otherwise it would succeed.