fix: remove unsupported sql field from agent-memory-rag Database

CNPG version on cluster does not support .spec.sql on Database CR.
The rag-init-job.yaml already handles RAG schema initialization separately.

Unblocks Flux dry-run for agent-memory-rag.

apps/base/customer1/hermes-db/agent-memory-rag-db.yaml

@@ -8,5 +8,3 @@ spec:
     name: hermes-pgdb
   name: agent_memory
   owner: memory
-  sql:
-    - "@rag-db-init.sql"