• [Feature] Add WaterDrop::ConnectionPool for efficient connection pooling using the proven connection_pool gem.
• [Feature] Add WaterDrop.instrumentation class-level instrumentation for producer lifecycle events. This allows external libraries to subscribe to producer.created and producer.configured events without needing producer instance references, enabling middleware injection and configuration by libraries like Datadog tracing.
• [Change] Remove Ruby 3.1 specs according to the EOL schedule.