Remove P256Kyber768Draft00PQKex curve from nonFips curve preferences and add tests to verify that the advertised curves are the same as the curve preferences we set.
Closes TUN-9161
## Summary
Nowadays, Cloudflared only supports X25519Kyber768Draft00 (0x6399,25497) but older versions may use different preferences.
For FIPS compliance we are required to use P256Kyber768Draft00 (0xfe32,65074) which is supported in our internal fork of [Go-Boring-1.22.10](https://bitbucket.cfdata.org/projects/PLAT/repos/goboring/browse?at=refs/heads/go-boring/1.22.10 "Follow link").
In the near future, Go will support by default the X25519MLKEM768 (0x11ec,4588) given this we may drop the usage of our public fork of GO.
To summarise:
* Cloudflared FIPS: QUIC_CURVE_PREFERENCES=65074
* Cloudflared non-FIPS: QUIC_CURVE_PREFERENCES=4588
Closes TUN-8855
