Merge pull request #660 from sirosen/switch-to-grouped-monthly-dependabot-gha

Switch to monthly grouped GHA dependabot updates

Author: sirosen

.github/dependabot.yml

@@ -7,4 +7,8 @@ updates:
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
-      interval: "weekly"
+      interval: "monthly"
+    groups:
+      github-actions:
+        patterns:
+          - "*"