Remove protected_ref requirement in trust policy (#9824)

Author: sarahchen6

.github/chainguard/self.update-jmxfetch-submodule.create-pr.sts.yaml

@@ -5,7 +5,6 @@ subject: repo:DataDog/dd-trace-java:ref:refs/heads/master
 claim_pattern:
   event_name: (schedule|workflow_dispatch)
   ref: refs/heads/master
-  ref_protected: "true"
   job_workflow_ref: DataDog/dd-trace-java/\.github/workflows/update-jmxfetch-submodule\.yaml@refs/heads/master
 
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