Remove peer-service-mapping declarative_name from r2dbc metadata

The bridge exposes otel.instrumentation.common.peer-service-mapping as a structured list at java.common.service_peer_mapping (list of peer/service_name entries), not as a flat map string. DeclarativeConfigValidationTest treats the 'map' type as a getString lookup, which fails for this mapping. Other metadata.yaml files intentionally omit declarative_name for this property; align r2dbc with that convention.

Author: trask

instrumentation/r2dbc-1.0/metadata.yaml

@@ -29,7 +29,6 @@ configurations:
     type: boolean
     default: false
   - name: otel.instrumentation.common.peer-service-mapping
-    declarative_name: java.common.service_peer_mapping
     description: Used to specify a mapping from host names or IP addresses to peer services.
     type: map
     default: ""