update github actions automatically (#15225)

Author: dprotaso

.github/dependabot.yaml

@@ -0,0 +1,8 @@
+# Set update schedule for GitHub Actions
+version: 2
+updates:
+- package-ecosystem: "github-actions"
+  directory: "/"
+  schedule:
+    # Check for updates to GitHub Actions every week
+    interval: "weekly"