No `libumka_static.a` in the Linux release folder

[vtereshkov]

libumka_static.a is removed before copying to the release folder:

https://github.com/vtereshkov/umka-lang/commit/0d108f9976dffebcba2f91b5b3c8bd88d41fbf75#diff-1c9153dd6483e04621e6d4cebd3908594e7ac119cf306c11834cc59924498d55R20

@marekmaskarinec We should either restore libumka_static.a in the Linux release folder, or remove it from Windows releases as well if nobody is using them.