Changed action trigger to run on PR

.github/workflows/e2e_tests_preview.yml

@@ -6,7 +6,7 @@ on:
 #            - opened
 #            - synchronize
 #            - ready_for_review
-    push:
+    pull-request:
 
 env:
     AWS_REGION: ca-central-1 # set this to your preferred AWS region, e.g. us-west-1
@@ -151,6 +151,6 @@ jobs:
             -   name: Create report and post on PR
                 uses: peter-evans/create-or-update-comment@v3
                 with:
-                    issue-number: ${{ github.event.pull_request.number }}
+                    issue-number: ${{ github.event.number }}
                     body-path: cypress/reports/test_results.md
                     token: ${{ secrets.PERSONAL_GITHUB_ACCESS_TOKEN }}