Auto merge of #112633 - Kobzol:ci-msvc-merge, r=pietroalbini

CI: merge `msvc` test CI jobs

Merges `msvc` jobs together to save CI time. Currently, both runners take about 1h 15 minutes, but nowadays it should be possible to just run everything in a single job.

CI run: https://github.com/rust-lang/rust/actions/runs/5272144087/jobs/9534015536?pr=112633 (both finish under ~1h 35 minutes)

After this change, we no longer test both `x.py` and `x.ps1`, but I don't suppose that it's worth it to spend 1.5 hours of additional CI time just for that. I suggest to run all tests using e.g. `x.py` and then run just `x.ps1 test --stage 2 --force-rerun tests/<single-quick-test>`.
Also I'm not sure if it's worth it to keep using the Makefile for this.

Author: bors