Update the `gix` family of crates to avoid the vulnerability reported in
[CVE-2025-31130].
Since `gix-hash` is used in two places, its version definition was moved to the
top-level `Cargo.toml`. `cargo` warned that `default-features` not being defined
in the top-level could result in a future error, so that was carried along with
it. This did not affect the build of `radicle-fetch`.
[CVE-2025-31130]: https://www.cve.org/CVERecord?id=CVE-2025-31130
For further details on the crate see its documentation in
`crates/radicle-oid/src/lib.rs`.
Changes to `crates/radicle{,-crypto}/Cargo.toml` are to preserve the
default features of their dependencies `serde` and `schemars`,
which are disabled to support `radicle-oid` being `no_std`.
Fintan Halpenny
Lorenz Leutgeb