feat(KSA-Dafny): System Key Handler #1901

	# This workflow checks if you are checking in dafny code
	# with the keyword {:only}, it adds a message to the pull
	# request to remind you to remove it.
	name: Check {:only} decorator presence

	on:
	pull_request:

	jobs:
	grep-only-verification-keyword:
	runs-on: ubuntu-latest
	permissions:
	issues: write
	pull-requests: write
	steps:
	- uses: actions/checkout@v3
	with:
	fetch-depth: 0

	- name: Check only keyword
	id: only-keyword
	shell: bash
	run:
	# checking in code with the dafny decorator {:only}
	# will not verify the entire file or maybe the entire project depending on its configuration
	# This action checks if you are either adding or removing the {:only} decorator and posting on the pr if you are.
	echo "ONLY_KEYWORD=$(git diff origin/main origin/${GITHUB_HEAD_REF} */.dfy \| grep -i {:only})" >> "$GITHUB_OUTPUT"

	- name: Check if ONLY_KEYWORD is not empty
	id: comment
	env:
	PR_NUMBER: ${{ github.event.number }}
	GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
	ONLY_KEYWORD: ${{ steps.only-keyword.outputs.ONLY_KEYWORD }}
	if: ${{env.ONLY_KEYWORD != ''}}
	run: \|
	COMMENT="It looks like you are adding or removing the dafny keyword {:only}.\nIs this intended?"
	COMMENT_URL="https://api.github.com/repos/${{ github.repository }}/issues/${PR_NUMBER}/comments"
	curl -s -H "Authorization: token ${GITHUB_TOKEN}" -X POST $COMMENT_URL -d "{\"body\":\"$COMMENT\"}"
	exit 1

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