Update crs-k/stale-branches action to v7 (#54)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

actions/clean-up-repo/action.yml

@@ -62,7 +62,7 @@ runs:
 
     - name: Clean branches
       id: cleanup_branches
-      uses: crs-k/stale-branches@v6.0.2
+      uses: crs-k/stale-branches@v7.0.0
       with:
         repo-token: ${{ inputs.token }}
         days-before-stale: ${{ inputs.days-before-branch-stale }}