GHSA-xwwf-m8fg-p9q2: RabbitMQ amqp091-go: Denial of Service via Sub-Spec Frame Size Negotiation

## Summary A Denial of Service (DoS) vulnerability exists in the AMQP client's connection negotiation logic. The AMQP specification explicitly mandates a strict minimum frame size of 4096 bytes to prevent pathological packet fragmentation. While the library defines a `frameMinSize = 4096` constant, the connection negotiation loop fails to enforce this boundary, blindly accepting whatever maximum frame size (`FrameMax`) the server advertises during the handshake. …