ci: verify that the Git and Scalar executables work in Nano Server

[dscho]

It was reported in git-for-windows/git#4052 that Git for Windows v2.38.0 introduced a regression (fixed in git-for-windows/git#4074) where git.exe could no longer be run in Nano Server containers.

Let's add a workflow that verifies that Git for Windows does not regress on this in the future.

The CI run will necessarily fail at the moment, as Git for Windows v2.38.1 was released without any fix for Nano Server, and will print helpful information as to any missing symbol, as demonstrated by this run.

As demonstrated by this run (which uses the artifacts produced by a build of the PullRequest that fixes the issue), the CI run will start succeeding once we build a new Git version after merging said PR.

[dscho]

Seems to work with ContainerAdministrator, too, so I'll take that one.

[dscho]

Now we have to wait before merging this PR until Git v2.38.2 is published (and hence, Git for Windows v2.38.2), or v2.39.0, or that there are more reasons than the regression on Nano Server that would justify a Git for Windows v2.38.1(2). We have to wait because the workflow runs would fail without any new mingw-w64-git version (which we traditionally integrate into git-sdk-64 only when publishing a new Git for Windows version).

[dscho]

We have to wait because the workflow runs would fail without any new mingw-w64-git version

We now have a v2.39.0-rc0, I rebased the branch, and the test passes: https://github.com/dscho/git-sdk-64/actions/runs/3539679536/jobs/5941865217

Now I only need to fix the (unrelated) check-for-missing-dlls check before merging this here PR.

[dscho]

Now I only need to fix the (unrelated) check-for-missing-dlls check before merging this here PR.

This is the PR that does that: git-for-windows/build-extra#445