ci: add push event to codeql chainguard (#15841)

Enables codeql runs triggered on github push events

Author: emmettbutler

.github/chainguard/codeql.sts.yaml

@@ -6,7 +6,7 @@ claim_pattern:
   ref: ".+"
   ref_path: "refs/heads/.+"
   ref_protected: "true"
-  pipeline_source: "(web|schedule)"
+  pipeline_source: "(web|schedule|push)"
   ci_config_ref_uri: "gitlab.ddbuild.io/DataDog/apm-reliability/dd-trace-py//.gitlab-ci.yml@refs/heads/.+"
 permissions:
   security_events: write