Make sure tox_on_install() hook is called in UvVenvLockRunner._setup_env()

[Viicos]

Fixes #187.
Fixes tox-dev/tox-gh#175.

self._install() is doing the same thing, but also calls the hook beforehand.

[gaborbernat]

Can you please add the task to validate against such regressions?

[Viicos]

Any guidance on how to do so? Should I setup some kind of mock plugin that emulates tox-gh and make assertions on the hook calls (tox_on_install(), etc)?

[gaborbernat]

Any guidance on how to do so? Should I setup some kind of mock plugin that emulates tox-gh and make assertions on the hook calls (tox_on_install(), etc)?

Yes, there are example of this in the test suite.

[Viicos]

I've had a look but did not find any existing test setting up another custom plugin, and it's going to take me some time to fully understand the test logic of the codebase. I'll put this on hold.