ci: restore pull_request trigger for e2e tests

Temporarily restore pull_request trigger until the gate workflow
is merged to main. The gate workflow will handle ok-to-test gating
for external contributors once it exists on the target branch.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: clubanderson

.github/workflows/ci-e2e-openshift.yaml

@@ -6,6 +6,11 @@ permissions:
   packages: write
 
 on:
+  # Direct trigger on PRs (temporary until gate workflow is on main)
+  pull_request:
+    branches:
+      - main
+      - dev
   # Called by the gate workflow after ok-to-test approval
   workflow_call:
     inputs: