Add some claim pattern back

Author: sarahchen6

.github/chainguard/self.pin-system-tests.create-pr.sts.yaml

@@ -3,6 +3,8 @@ issuer: https://token.actions.githubusercontent.com
 subject_pattern: repo:DataDog/dd-trace-java:ref:refs/heads/.+
 
 claim_pattern:
+  event_name: (push|workflow_dispatch)
+  ref: refs/heads/.+
   job_workflow_ref: DataDog/dd-trace-java/\.github/workflows/pin-system-tests\.yaml@.+
 
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