Address pinned libcrux / hax-lib dependency patching

[rocodes]

Currently we pin a version of many libcrux crates to our own fork due to a need for hax-lib v0.3.7 to be released and a dependency resolution issue in hpke-rs. hax-lib 0.3.7 is released, but the referenced PR that we mention in comments we are waiting for, celabshq/libcrux#1478, was closed.

This issue is for tracking what remains to unpin libcrux and hpke-rs and ensure we can stay on regular supported versions of each of those.

[cfm]

I can give this a shot from celabshq/libcrux#1506, which would theoretically let us pin an upstream (rather than forked) commit until a new version of the crate is released....

[rocodes]

my tiny hax-lib PR was merged, so pinning a recent commit will allow us to use refinement_type in our no_std environment, which will make it easier to get panic freedom proofs for our message types. So yes if we get to this it should unlock a few nice things :)