Update references to Steinberg ASIO SDK filename

[pljones]

There is also an unresolved issue regarding the version update of ASIO SDK, where the auto-generated PR doesn't build because Steinberg has changed the zip file naming convention and contents directory. I've done some work on that, but still need to finish it off.

Have we got an issue / PR for that? I remember something but I must have forgotten to put it on the project board.

https://github.com/jamulussoftware/jamulus/compare/main...softins:jamulus:sdk-filename found it.

Originally posted by @pljones in #3443