fix: fix CEL expression and remove release-right-meow SA

Fix the on-cel-expression to use the correct CEL variables:
- Use 'event' and 'target_branch' (not 'pac.target_branch' which is
  only available in {{ cel: }} param substitution, not in
  on-cel-expression matching)
- Use 'target_branch' without 'refs/heads/' prefix (PAC strips it)
- Use '|' literal block scalar instead of '>' folding to avoid
  trailing newline issues
- Add 'event == "push"' for explicitness

Also remove the release-right-meow ServiceAccount from both
PipelineRuns. It is a leftover from the old EventListener-based
release flow. All release secrets are mounted as workspaces, so
the default SA is sufficient.

Author: vdemeester

.tekton/release-patch.yaml

@@ -32,8 +32,6 @@ metadata:
 spec:
   pipelineRef:
     name: operator-release
-  taskRunTemplate:
-    serviceAccountName: release-right-meow
   params:
     - name: package
       value: github.com/tektoncd/operator

.tekton/release.yaml

@@ -32,16 +32,14 @@ metadata:
     # so the branch filter MUST be included in the CEL expression.
     pipelinesascode.tekton.dev/on-event: "[push]"
     pipelinesascode.tekton.dev/on-target-branch: "[refs/heads/release-v*]"
-    pipelinesascode.tekton.dev/on-cel-expression: >
-      has(body.created) && body.created == true &&
-      pac.target_branch.startsWith("refs/heads/release-v")
+    pipelinesascode.tekton.dev/on-cel-expression: |
+      event == "push" && has(body.created) && body.created == true &&
+      target_branch.startsWith("release-v")
     pipelinesascode.tekton.dev/pipeline: "tekton/operator-release-pipeline.yaml"
     pipelinesascode.tekton.dev/max-keep-runs: "5"
 spec:
   pipelineRef:
     name: operator-release
-  taskRunTemplate:
-    serviceAccountName: release-right-meow
   params:
     - name: package
       value: github.com/tektoncd/operator