ci: update dependabot config

Changed the update schedule for GitHub Actions and npm from weekly to monthly. Added groups for better organization of updates.

.github/dependabot.yml

@@ -3,19 +3,27 @@ updates:
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
-      interval: "weekly"
+      interval: "monthly"
       day: "sunday"
     labels:
       - "dependencies"
-
+    groups:
+      github-actions:
+        applies-to: version-updates
+        patterns:
+          - "*"
   - package-ecosystem: "npm"
     directory: "/"
     schedule:
-      interval: "weekly"
+      interval: "monthly"
       day: "sunday"
     ignore:
       - dependency-name: "*"
         update-types: ["version-update:semver-major"]
     labels:
       - "dependencies"
- 
+    groups:
+      npm:
+        applies-to: version-updates
+        patterns:
+          - "*"