Stop producing TaskRun attestations

https://issues.redhat.com/browse/HACBS-2209

RHTAP is only concerned with PipelineRun attestations. The TaskRun
attestations add noise and potential confusion to users. Also, the
PipelineRun attestation already contains all the data found on the
TaskRun attestation.

Signed-off-by: Luiz Carvalho <[email protected]>

Author: lcarva

operator/gitops/argocd/pipeline-service/tekton-chains/chains-config.yaml

@@ -8,9 +8,11 @@ metadata:
 data:
   # See https://tekton.dev/docs/chains/config/
 
-  # Configure TaskRun attestation
+  # Configure TaskRun attestation. RHTAP does not leverage the TaskRun
+  # attestations. This tells Tekton Chains to not store them in the OCI
+  # registry.
   artifacts.taskrun.format: "in-toto"
-  artifacts.taskrun.storage: "oci"
+  artifacts.taskrun.storage: ""
 
   # Configure PipelineRun attestation
   artifacts.pipelinerun.format: "in-toto"