fix(ci): use PR head SHA instead of merge commit SHA

For pull_request events, checkout and tag images using the PR head SHA
(github.event.pull_request.head.sha) instead of the merge commit SHA
(github.sha). This ensures the image contains the actual PR changes.

🤖 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

@@ -50,6 +50,9 @@ jobs:
     steps:
       - name: Checkout source
         uses: actions/checkout@v4
+        with:
+          # Use PR head SHA for pull_request events, otherwise default
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
 
       - name: Log in to GHCR
         uses: docker/login-action@v3
@@ -63,7 +66,8 @@ jobs:
         env:
           REGISTRY: ghcr.io
           IMAGE_NAME: ${{ github.repository }}
-          GIT_REF: ${{ github.sha }}
+          # Use PR head SHA for pull_request events, otherwise github.sha
+          GIT_REF: ${{ github.event.pull_request.head.sha || github.sha }}
         run: |
           # Build image with git ref tag for this PR
           # Use first 8 chars of the git ref
@@ -99,6 +103,9 @@ jobs:
     steps:
       - name: Checkout source
         uses: actions/checkout@v4
+        with:
+          # Use PR head SHA for pull_request events, otherwise default
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
 
       - name: Extract Go version from go.mod
         run: sed -En 's/^go (.*)$/GO_VERSION=\1/p' go.mod >> $GITHUB_ENV