Update the dependabot ignore configuration

Add crazy-max/ghaction-github-labeler as a commented out dependency to
ignore in the dependabot configuration file. This should be enabled in
downstream projects to consolidate updating this Action to the
cisagov/skeleton-generic repository.

.github/dependabot.yml

@@ -17,6 +17,7 @@ updates:
     #   - dependency-name: actions/checkout
     #   - dependency-name: actions/setup-go
     #   - dependency-name: actions/setup-python
+    #   - dependency-name: crazy-max/ghaction-github-labeler
     #   - dependency-name: hashicorp/setup-terraform
     #   - dependency-name: mxschmitt/action-tmate