snowbridge: Update alloy-core (#6808)

I am planning to use `alloy_core` to implement precompile support in
`pallet_revive`. I noticed that it is already used by snowbridge. In
order to unify the dependencies I did the following:

1. Switch to the `alloy-core` umbrella crate so that we have less
individual dependencies to update.
2. Bump the latest version and fixup the resulting compile errors.