fix(redis-otel): Use NO_OP instead of CREATE_UNINSTRUMENTED for clust…

[vagrawal-newrelic]

Summary

Fixes CI failure introduced by the Redis OTel cluster candidate relationship file. Changes onMiss action from CREATE_UNINSTRUMENTED to NO_OP for the REDISCLUSTER candidate category.

Problem

The REDISCLUSTER.stg.yml candidate relationship used CREATE_UNINSTRUMENTED which requires a corresponding uninstrumented-rediscluster/definition.stg.yml file to exist. This file was missing, causing the validate_uninstrumented_definitions_exists CI check to fail for all PRs.

Fix

Changed to action: NO_OP — when an APM service references a Redis cluster that doesn't have an instrumented entity, do nothing instead of creating a placeholder. This matches the approach used by Kafka topics (PR #2994).

Why NO_OP over CREATE_UNINSTRUMENTED

• Avoids creating potentially confusing placeholder entities for customers
• Simpler — no additional uninstrumented entity definition file needed
• Consistent with the Kafka OTel pattern (KAFKATOPIC.stg.yml)
• Relationships still work correctly when both entities are instrumented

[entityBot]

We don't think these changes require an API Review Board (ARB) review, so it is not required to merge this PR. Note that all API changes do require one: if you believe this PR needs an ARB review, please create the ticket and add the ARB:pending label. Reach #api-review-board in case of doubts.