Add zstd to encoding check

[M-arcus]

Fixes #124

[soulgalore]

Hi @M-arcus thank you for the fixes! I'm on vacation and need to fix a thing in the coach before this is released, I'll try to do that fix the coming days (the tests/GitHub actions is broken at the moment).

[M-arcus]

Thank you, @soulgalore.
I have added a PR that fixes the pipeline in #131.
Sadly, the test is still broken for Node 20

[soulgalore]

@M-arcus thank you again, your fixes. There are some things that are broken in the testing but I want to avoid spending time on that now since I plan to do a new implementation of the coach early December this year (there are so much that is old in the code and I want to get rid of that).