This release fixes a critical bug where FunctionClauseError was thrown
during GRPC connection cleanup, causing GenServer crashes.

Key fixes:
- Modified grpc_connection_pool worker to handle Gun connections safely
- Bypasses problematic pattern matching in GRPC v0.11.5 disconnect code
- Improved connection pool stability during shutdown cycles
- Added comprehensive tests for disconnect behavior

This resolves crashes with error: 'no function clause matching in
anonymous fn/1 in GRPC.Client.Connection.handle_call/3'