Make concurrency group in CI less specific

Since 93f4cfc the concurrency group also
handles repository dispatch events, but it incorrectly includes the SHA,
making it too specific. SHA should only be used for events other than
pull requests or repository dispatch.

.github/workflows/ci.yml

@@ -42,7 +42,11 @@ concurrency:
   # Cancel all workflow runs except latest within a concurrency group. This is achieved by defining a concurrency group for the PR.
   # Non-PR builds have singleton concurrency groups.
   # When triggered by the repository_dispatch, add the expected SHA to avoid cancelling the run from the PR.
-  group: ${{ github.workflow }}-${{ github.event_name == 'pull_request' && github.event.number || github.sha }}-${{ github.event_name == 'repository_dispatch' && github.event.client_payload.slash_command.args.named.sha || github.sha }}
+  group: |
+    workflow=${{ github.workflow }},
+    pr_number=${{ github.event_name == 'pull_request' && github.event.number || 'NA' }},
+    dispatch_sha=${{ github.event_name == 'repository_dispatch' && github.event.client_payload.slash_command.args.named.sha || 'NA' }},
+    commit_sha=${{ github.event_name != 'pull_request' && github.event_name != 'repository_dispatch' && github.sha || 'NA' }}
   cancel-in-progress: true
 
 jobs: