check-cherry-picks.sh maintainer script: add clarifying message regarding differences found

maintainers/scripts/check-cherry-picks.sh

···
 
           $range_diff_common --color
 
+          echo "Note this should not necessarily be treated as a hard fail, but a reviewer's attention should" \
+            "be drawn to it and github actions have no way of doing that but to raise a 'failure'"
           problem=1
         else
           echo "  ✔ $original_commit_sha highly similar to $new_commit_sha"