Add test CI for configlet fetching

[BNAndras]

Closes #108

[IsaacG]

What's the purpose of this CI? What purpose does it serve?

[BNAndras]

It tests if the configlet reusable workflow can fetch configlet. The configlet repo itself checks whether configlet can be fetched, but nothing is testing if this workflow works.

[kotp]

The test relies on the response code for the option --version. This relies on someone not deciding that it should exit with signal other than 0.

It might be enough, but we might check for something more significant than "command with this name evaluates with a success signal"

[BNAndras]

Then the CI fails with a nonzero exit code, and we investigate the breakage to determine whether the issue lies with the workflow or configlet itself.

What more significant test are you proposing? The CI is testing that configlet can be fetched and executed successfully, not to test its functionality. The specific command isn’t particularly important, but checking the version is simple enough.

[glennj]

And it's being fetched into a new container. Unlikely there would be any other "configlet" there.