Enable Dependabot (github#654)

* Create/Update dependabot.yaml

* Apply suggestion from @Copilot

Co-authored-by: Copilot <[email protected]>

---------

Co-authored-by: Copilot <[email protected]>

Author: 2 people

.github/dependabot.yml

@@ -13,3 +13,7 @@ updates:
     directory: "/"
     schedule:
       interval: "weekly"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"