Removes the redundant MAXIMUM_MESSAGE_SIZE check from the HTTP transport layer. The validation was performed after loading the entire request body into memory, providing no actual memory protection.

Changes

• Removed post-body-read size validation from _handle_post_request()

Rationale

• Check executed after await request.body(), making it ineffective for memory exhaustion prevention
• ASGI servers handle flow control via backpressure mechanisms
• Simplifies codebase by removing ineffective validation