Cancel superseded runs of the remaining workflows (#5579)

Ubuntu, Windows, macOS, and CodeQL already cancel an older run of the same
workflow on the same ref. Check amalgamation, CIFuzz, Dependency Review,
Flawfinder, Semgrep, Scorecard, and the labeler did not, so every push
to a pull request left their earlier runs going. Give them the same
concurrency group. The labeler runs on pull_request_target, where
github.ref is the base branch, so it groups by pull request number.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

.github/workflows/cifuzz.yml

@@ -1,6 +1,10 @@
 name: CIFuzz
 on: [pull_request]
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
+  cancel-in-progress: true
+
 permissions:
   contents: read