Skip eslint workflow for internal pull requests

Refs:
- https://github.community/t/duplicate-checks-on-push-and-pull-request-simultaneous-event/18012/4
- 612732d587

.github/workflows/eslint.yml

@@ -6,6 +6,9 @@ jobs:
     lint:
         runs-on: ubuntu-latest
 
+        # Run for external PRs, but not on our own internal PRs as they'll be run by the push to the branch.
+        if: github.event_name == 'push' || github.event.pull_request.head.repo.full_name != 'DoctorMcKay/node-steamcommunity'
+
         strategy:
             matrix:
                 node-version: [10.x]