Test: Enable system certificate store test on windows

[reneme]

This test was disabled, because previous CI build machines didn't provide the necessary certificate in their root trust stores. ~~Maybe GitHub Actions does?~~ Turns out: GitHub Actions runners have the necessary certificate installed (D-TRUST Root Class 3 CA 2 EV 2009).

Obviously, I'll rebase this after #3007 is merged.

Those tests were previously disabled in:

• #1931
• #2280