Auto merge of #13117 - Byron:enable-tests, r=weihanglo

re-enable previously disabled tests with Windows-specific fix

Related to #11821 for which this is a fix.
However, it's probably not yet the optimal solution, depending on how `stderr` of subprocesses should be handled.

### Tasks

* [x] try to fix the issue with an env var.
    - Failure, as one warning remains that seems to originate from a C# HTTP client
* [x] figure out if `stderr` should be on or off by default - on by default like before, but now one can control it.
* [x] create a new `gix` release and use it here

### Review Notes

* Personally, I think `cargo` should keep `stderr` to be inherited so users can see potentially relevant warnings or errors provided by credential helpers. Thus this is still the default, but the tests that need it explicitly disabled `stderr` of credential helpers.

----

On Windows, `gix` will call the `git-credential-manager, but with
`stderr` set to `inherit` which makes any errors visible to the user,
just like `git` does.

```
1   1         Updating git repository `https://foo.bar/foo/bar`
    2    +warning: auto-detection of host provider took too long (>2000ms)
    3    +warning: see https://aka.ms/gcm/autodetect for more information.
    4    +fatal: A task was canceled.
    5    +warning: auto-detection of host provider took too long (>2000ms)
    6    +warning: see https://aka.ms/gcm/autodetect for more information.`
````

This, however, isn't what's desirable in tests sometimes, nor may
it be desirable in Cargo.

For now, it seems easiest to disable this particular feature that
issues the warning messages, even though a future `gix` update
should allow to control what to do with `stderr`.

Author: bors