Update wiremock to 0.6.4 (#14238)
<!--
Thank you for contributing to uv! To help us out with reviewing, please
consider the following:
- Does this pull request include a summary of the change? (See below.)
- Does this pull request include a descriptive title?
- Does this pull request include references to any relevant issues?
-->
## Summary
In e10881d49c8649a66f301af9052fd2bb17eb68d4, `uv` started using a fork
of the `wiremock` crate, https://github.com/astral-sh/wiremock-rs,
linking companion PR
https://github.com/LukeMathWalker/wiremock-rs/pull/159. That PR was
merged in `wiremock` 0.6.4, so this PR switches back to the crates.io
version of `wiremock`, with a minimum version of 0.6.4.
<!-- What's the purpose of the change? What does it do, and why? -->
## Test Plan
```
$ cargo run python install
$ cargo test
````
