ci(dependabot): update GitHub Action images automatically

.github/dependabot.yml

@@ -13,3 +13,15 @@ updates:
   commit-message:
     prefix: chore
     include: scope
+
+  - package-ecosystem: github-actions
+    directory: "/"
+    open-pull-requests-limit: 5
+    target-branch: master
+    schedule:
+      interval: weekly
+    reviewers:
+      - Deuchnord
+    commit-message:
+      prefix: ci
+      include: scope