Minor: Kernel 6.5: create it87.ko.zst

[juzi]

I just got Ubuntu Linux 23.10 with Kernel 6.5 and compiled the module again from the sources.
First it didn't work. Then I realized that it had copied the .ko file to the modules directory. After compressing it with
sudo zstd it87.ko
and overriding the existing file it worked again. Maybe you could include that in the build process.