Migrate GitHub Actions updates from TSCCR to Dependabot (#766)

configure dependabot to automatically update GitHub Actions dependencies

Author: nodyhub

.github/dependabot.yaml

@@ -29,10 +29,6 @@ updates:
         update-types:
           - minor
           - patch
-    # only update internal github actions, external github actions are handled
-    # by https://github.com/hashicorp/security-tsccr/tree/main/automation
-    allow:
-      - dependency-name: "hashicorp/*"
   - package-ecosystem: "docker"
     directory: "/"
     schedule: