Ability to force install `.so` files on macOS.

[igalklebanov]

Hey 👋

Thank you for this awesome package manager!

The package manager, by default, only downloads dylib files on Mac.

I'm setting it up in a project, and we're using libsql-server. After some trial and error, it appears that sqld doesn't support dylib files - only so files when using the --extensions-path flag.

After playing around with spec files, and overriding the Mac archives' names with Linux ones, I was able to make it download so files.

Would be great to have a CLI flag and lockfile prop that allows to specify that the target should be Linux, or that so files are required.