Potential denial-of-service vulnerability in ASGI requests via file upload limit bypass

An issue was discovered in 6.0 before 6.0.5 and 5.2 before 5.2.14. ASGI requests with a missing or understated `Content-Length` header can bypass the `FILE_UPLOAD_MAX_MEMORY_SIZE` limit, potentially loading large files into memory and causing service degradation. As a reminder, Django expects a limit to be configured at the web server level rather than solely relying on `FILE_UPLOAD_MAX_MEMORY_SIZE`. Earlier, unsupported Django series (such as 5.0.x, 4.1.x, and 3.2.x) were not evaluated and may also be affected. Django would like to thank Kyle Agronick for reporting this issue.