Remove Results prometheus config

Still not supported by the OSP operator. Removing temporary to allow
testing.
Also remove S3_HOSTNAME_IMMUTABLE, set to default value (false) anyway.

components/pipeline-service/development/main-pipeline-service-configuration.yaml

@@ -1006,9 +1006,6 @@ spec:
   tls_hostname_override: tekton-results-api-service.openshift-pipelines.svc.cluster.local
   db_enable_auto_migration: true
   server_port: 8080
-  prometheus_port: 9090
-  prometheus_histogram: true
-  s3_hostname_immutable: false
   options:
     deployments:
       tekton-results-watcher: