fix: checkout in comment bot workflow for CD pipeline (#181)

Author: aryarm

.github/workflows/comment_bot.yml

@@ -9,6 +9,9 @@ jobs:
     if: ${{ github.event.issue.pull_request }}    # check if the comments come from a pull request and exclude comments from issues
     runs-on: [ubuntu-latest]
     steps:
+      - name: Check out the repository
+        uses: actions/checkout@v3
+
       - name: Run Tests
         if: startsWith(github.event.comment.body, '/check')   # check that the comment startsWith the "/check" keyword
         uses: ./.github/workflows/tests.yml