added dependabot

Author: ustiugov

.github/dependabot.yml

@@ -0,0 +1,9 @@
+# Use https://dependabot.com/docs/config-file/validator/ to check for errors.
+version: 2
+updates:
+  # Enable version updates for Actions
+  - package-ecosystem: "github-actions"
+    # Look for `.github/workflows` in the `root` directory
+    directory: "/"
+    schedule:
+      interval: "weekly"