chore: tests only run on linux

temporary solution while i figure out what's wrong

Author: nik-rev

helix-vcs/src/git/blame.rs

@@ -191,6 +191,7 @@ pub fn blame_line(
 //
 // when the last line has no expected blame commit
 #[allow(unused_assignments)]
+#[cfg(target_os = "linux")]
 #[cfg(test)]
 mod test {
     use std::fs::File;