Updated MSTest.* from 3.7.3 to 3.8.0

[abatishchev]

Supersedes #238, #239 as both packages need to be updated simultaneously.

[abatishchev]

@loekd please take a look.

[loekd]

I've updated the dependabot configuration, so it groups updates to mstest packages. Hopefully that will prevent breaking pipelines in the future.

    groups:
      mstest-packages:
        patterns:
          - "MSTest.TestAdapter"
          - "MSTest.TestFramework"

[abatishchev]

Awesome! I didn't know you can do it!

But also, I don't see it has taken effect (maybe not yet): #242 and #243 were automatically created per package, not together. I'll see how it goes next time and let you know.

[loekd]

Found the docs here
Let's see if it works better for the next version indeed.