CTS issue workflow: Skip if PR has cherry-pick label

Changes that are being cherry-picked into an older version of the spec
don't need a separate CTS issue, as the CTS targets all versions from
SYCL 2020 onward.

.github/workflows/open_cts_issue.yml

@@ -13,8 +13,8 @@ on:
 jobs:
   create-issue:
     runs-on: ubuntu-latest
-    # Skip if this is a purely editorial PR
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'editorial') }}
+    # Skip if this is a purely editorial PR, or if the change is being cherry-picked into an older version of the spec
+    if: ${{ !contains(github.event.pull_request.labels.*.name, 'editorial') && !contains(github.event.pull_request.labels.*.name, 'cherry-pick') }}
     steps:
       - uses: actions/create-github-app-token@v1
         id: app-token