chore: Send Slack runs on schedule or if inputs.send_notification is true (#2342)

* job runs on schedule or if inputs.send_notification is true

* use github.event so it's converted to string

Author: oarbusi

.github/workflows/test-suite.yml

@@ -81,7 +81,7 @@ jobs:
 
   slack-notification:
     needs: [tests, clean-after]
-    if: ${{ !cancelled() && needs.tests.result == 'failure' && (inputs.send_notification == true || inputs.send_notification == 'true') }}
+    if: ${{ !cancelled() && needs.tests.result == 'failure' && !contains(github.event.inputs.send_notification, 'false') }}
     runs-on: ubuntu-latest
     permissions: {}
     steps: