Infra: Group github/codeql-action bumps into a single dependabot PR

Author: ebyhr

.github/dependabot.yml

@@ -34,3 +34,10 @@ updates:
       interval: "weekly"
     cooldown:
       default-days: 7
+    groups:
+      # The codeql-action init/autobuild/analyze steps must all run the
+      # same version - split PRs cause a version mismatch that fails the
+      # Analyze jobs. Group them so a single PR bumps all of them together.
+      codeql-action:
+        patterns:
+          - "github/codeql-action*"