Sync with Pro #1826

	name: check-submodule
	# this file is copied from semgrep-proprietary's check-submodule.yaml

	on: [pull_request]

	jobs:
	check-submodule:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout this repo
	uses: actions/checkout@v3
	with:
	submodules: true
	- name: Check that Semgrep interfaces submodule points to main
	uses: jtmullen/submodule-branch-check-action@v1
	with:
	# See https://github.com/marketplace/actions/submodule-branch-check for
	# docs
	path: "cli/src/semgrep/semgrep_interfaces"
	branch: "main"
	# Allow the submodule to point to any commit that has made it into
	# main, even if it's a commit on a separate branch that has since
	# been merged in.
	first_parent: false
	# Don't fetch full history. We could remove this to do a full clone or
	# increase the number if we start getting false positives, but our
	# branches are usually short-lived so this is probably sufficient.
	fetch_depth: "50"
	# Pass if the PR in question doesn't modify the submodule, even if it
	# would otherwise fail (i.e. if the submodule already points to
	# something off of main, then don't bother people making unrelated
	# changes).
	pass_if_unchanged: true
	# Don't check that the new commit is a descendent of the old commit.
	# Otherwise, if the submodule already points to a different branch,
	# this job would fail on the PR to return it to main. This way, the
	# job will simply fail if the PR updates `semgrep-interfaces` to point
	# to any non-`main` commit, and succeed otherwise.
	disable_progression: true

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