uv-cache: bump built-wheels cache version (#2715)

It turns out that #2712 did _not_ fix #2711. After I put up #2712, I
started trying to track down the specific change that caused the
failure. I had assumed at first that it was related to one of our `rkyv`
types, but it actually ended up being one of our msgpack caches. I think
the failure mode is still fundamentally the same idea: the cached data
changed in a way that is still valid msgpack, but got interpreted
differently after deserializing.

The specific change that caused this was the [removal of a field] from
our
metadata type.

Ideally we would just undo the change and add the field back. But that
change has already been shipped out to users. So I believe the only
plausible choice at this point is to bump the `built-wheels` cache. This
will unfortunately mean that `uv` will need to re-build wheels.

Fixes #2711

[removal of a field]:
365c292#diff-e42586829f9c2cdbb909bedc5cf95691cc415247f2cbc2ebeb80d887020457bbL29

crates/uv-cache/src/lib.rs

@@ -594,7 +594,7 @@ pub enum CacheBucket {
 impl CacheBucket {
     fn to_str(self) -> &'static str {
         match self {
-            Self::BuiltWheels => "built-wheels-v1",
+            Self::BuiltWheels => "built-wheels-v2",
             Self::FlatIndex => "flat-index-v0",
             Self::Git => "git-v0",
             Self::Interpreter => "interpreter-v0",