ci: group dependabot updates (boto#4777)

Author: jonathan343

.github/dependabot.yml

@@ -9,9 +9,17 @@ updates:
         update-types: ["version-update:semver-patch"]
     cooldown:
       default-days: 7
+    groups:
+      github-actions:
+        patterns:
+          - "*"
   - package-ecosystem: "pre-commit"
     directory: "/"
     schedule:
       interval: "weekly"
     cooldown:
       default-days: 7
+    groups:
+      pre-commit:
+        patterns:
+          - "*"