curl error with `cabal upload -d` (regression in 3.14)

It looks like uploading documentation got broken:
```
$ cabal-3.12.1.0 upload -d /Users/abel/bin/src/test-framework/dist-newstyle/test-framework-0.8.2.2-docs.tar.gz
Uploading documentation
/Users/abel/bin/src/test-framework/dist-newstyle/test-framework-0.8.2.2-docs.tar.gz...
Documentation successfully uploaded for package candidate...

$ cabal-3.14.2.0 upload -d /Users/abel/bin/src/test-framework/dist-newstyle/test-framework-0.8.2.2-docs.tar.gz
Uploading documentation
/Users/abel/bin/src/test-framework/dist-newstyle/test-framework-0.8.2.2-docs.tar.gz...
Error: cabal-3.14.2.0: '/usr/bin/curl' exited with an error:
curl: (56) chunk hex-length char not a hex digit: 0xd

$ curl --version
curl 8.7.1 (x86_64-apple-darwin24.0) libcurl/8.7.1 (SecureTransport) LibreSSL/3.3.6 zlib/1.2.12 nghttp2/1.64.0
Release-Date: 2024-03-27
Protocols: dict file ftp ftps gopher gophers http https imap imaps ipfs ipns ldap ldaps mqtt pop3 pop3s rtsp smb smbs smtp smtps telnet tftp
Features: alt-svc AsynchDNS GSS-API HSTS HTTP2 HTTPS-proxy IPv6 Kerberos Largefile libz MultiSSL NTLM SPNEGO SSL threadsafe UnixSockets
```
(I also tried cabal-3.14.1.0/1, same problem.)
````
curl: (56) chunk hex-length char not a hex digit: 0xd
````