Consider using `eps1lon/actions-label-merge-conflict` GitHub action to check merge conflicts

[Jefffrey]

Is your feature request related to a problem or challenge?

We have a TODO item in our labeler workflow:

datafusion/.github/workflows/labeler.yml

Lines 55 to 65 in 58bc749

	# TODO: Enable this when eps1lon/actions-label-merge-conflict is available.
	# - name: Checks if PR needs rebase
	# if: |
	# github.event_name == 'push' ||
	# (github.event_name == 'pull_request_target' &&
	# (github.event.action == 'opened' ||
	# github.event.action == 'synchronize'))
	# uses: eps1lon/actions-label-merge-conflict@releases/2.x
	# with:
	# dirtyLabel: "needs-rebase"
	# repoToken: "${{ secrets.GITHUB_TOKEN }}"

I think we can use this action if we pin it to a specific hash, e.g.

datafusion/.github/workflows/rust.yml

Line 755 in 1629420

uses: taiki-e/install-action@0aa4f22591557b744fe31e55dbfcdfea74a073f7 # v2

Describe the solution you'd like

Consider enabling this

Describe alternatives you've considered

If we don't see value in having this action then remove the commented code

Additional context

No response