Create Dependabot update task

Dependabot keeps repo dependencies updated. For this configuration, we are just updating GitHub Actions. This can extend into Gradle if needed but this is just to keep individual Actions updated.

.github/dependabot.yml

@@ -0,0 +1,7 @@
+version: 2
+updates:
+  # Dependabot updates for GitHub Actions
+  - package-ecosystem: github-actions
+    directory: "/"
+    schedule:
+      interval: "weekly"