ML-DSA support

[dgloe-hpe]

It would be useful if libjwt supported the new quantum resistant ML-DSA signing algorithms (if using a cryptographic library that implements them).

See here for more information about the ML-DSA algorithms: https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.204.pdf
AWS already supports signing JWTs with ML-DSA: https://aws.amazon.com/blogs/security/how-to-create-post-quantum-signatures-using-aws-kms-and-ml-dsa/

[benmcollins]

This looks fairly straight forward to implement with OpenSSL 3.5 and GnuTLS 3.8.9 or later versions.

However, most everything appears to be experimental, so an initial implementation in LibJWT would be marked the same, and only be enabled if manually turned on via a cmake option flag.