Allow '*' as a value to match all hosts, and provide
`reqwest_blocking_get` for uv tests, so that they also respect
UV_INSECURE_HOST (since they respect `ALL_PROXY`).
This lets those tests pass with a forward proxy - we can think about
setting a root certificate later so that we don't need to disable
certificate verification at all.
---
I tested this locally by running:
```bash
GIT_SSL_NO_VERIFY=true ALL_PROXY=localhost:8080 UV_INSECURE_HOST="*" cargo nextest run sync_wheel_path_source_error
```
With my forward proxy showing:
```
2024-10-09T18:20:16.300188Z INFO fopro: Proxied GET cc2fedbd88/cffi-1.17.1-cp310-cp310-macosx_11_0_arm64.whl (headers 480.024958ms + body 92.345666ms)
2024-10-09T18:20:16.913298Z INFO fopro: Proxied GET https://pypi.org/simple/pycparser/ (headers 509.664834ms + body 269.291µs)
2024-10-09T18:20:17.383975Z INFO fopro: Proxied GET 5f610ebe42/pycparser-2.21-py2.py3-none-any.whl.metadata (headers 443.184208ms + body 2.094792ms)
```
As per
https://matklad.github.io/2021/02/27/delete-cargo-integration-tests.html
Before that, there were 91 separate integration tests binary.
(As discussed on Discord — I've done the `uv` crate, there's still a few
more commits coming before this is mergeable, and I want to see how it
performs in CI and locally).
