Update dependabot.yml

Author: kruskall

.github/dependabot.yml

@@ -5,7 +5,7 @@ updates:
   - package-ecosystem: "github-actions"
     directories:
       - "/"
-      - "/.github/actions/*"
+      - "/.github/workflows/*"
     reviewers:
       - "elastic/observablt-ci"
     schedule: