build: add GitHub Actions to Dependabot for real this time

.github/dependabot.yml

@@ -4,8 +4,13 @@ updates:
   - package-ecosystem: "npm"
     # Look for `package.json` and `lock` files in the `root` directory
     directory: "/"
-    # Check the npm registry for updates every day (weekdays)
+    # Check the npm registry for updates every weekday
     schedule:
       interval: "daily"
     ignore:
       - dependency-name: aws-sdk
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every weekday
+      interval: "daily"