Call New GetCultureInfo API When Validating Cultures

[benvillalobos]

Fixes https://github.com/dotnet/msbuild/issues/3897

Context

Changes Made

Testing

Notes

Haven't tested this locally.

[benvillalobos]

Talked with Tarek, turns out we should be using a different API altogether: https://docs.microsoft.com/en-us/dotnet/api/system.globalization.cultureinfo.getcultureinfo?view=net-6.0#system-globalization-cultureinfo-getcultureinfo(system-string-system-boolean)

[benvillalobos]

@tarekgh I tried out a few test cases for aliases in codingdinosaur's writeup, and I'm seeing interesting results:

The good news is they both see zh-TW as a valid culture, which is strictly improved from before 😄 any thoughts on the failing cases? are those aliases expected not to be detected?

[tarekgh]

@BenVillalobos the failing cases is because the culture name using _ and not -.

[benvillalobos]

the failing cases is because the culture name using _ and not -.

thanks!

[benvillalobos]

This is the first I've seen CanShutdownServerProcess fail. This might be a flaky test, but it's too early to tell. It looks very unrelated to what this change is about.

[Forgind]

@BenVillalobos, I told it to rerun. I suspect flakiness.

@rokonec, see BenVillalobos's comment—second instance today.