Run preview action only in the main repository

Author: steff456

.github/workflows/preview.yml

@@ -1,6 +1,7 @@
 on: [status]
 jobs:
   circleci_artifacts_redirector_job:
+    if: ${{ github.repository_owner == 'data-apis' }}
     runs-on: ubuntu-latest
     name: Run CircleCI artifacts redirector
     steps:
@@ -14,4 +15,4 @@ jobs:
           job-title: Check the rendered docs here!
       - name: Array API preview
         run: |
-          curl --fail ${{ steps.step1.outputs.url }} | grep $GITHUB_SHA
+          curl --fail ${{ steps.step1.outputs.url }} | grep $GITHUB_SHA