Disable dependabot for github actions

We don't get much value from dependabot for github actions - they basically just work until they don't, and then we can upgrade as needed. It doesn't know how to update our workflow-gen tool, so it isn't convenient at all.

.github/dependabot.yml

@@ -10,7 +10,3 @@ updates:
     schedule:
       interval: "daily"
 
-  - package-ecosystem: "github-actions" 
-    directory: "/" # Location of package manifests
-    schedule:
-      interval: "daily"