DEV: Run flake check only on discourse/discourse (#27350)

script/get_github_workflow_run_job_id.rb would fail on forks anyway

.github/workflows/tests.yml

@@ -306,7 +306,7 @@ jobs:
 
       - name: Check for flaky tests report
         id: check-flaky-spec-report
-        if: always()
+        if: always() && github.repository == 'discourse/discourse'
         run: |
           if [ -f tmp/turbo_rspec_flaky_tests.json ]; then
             echo "exists=true" >> $GITHUB_OUTPUT