test: disable uds conflict test on redox

It's just too slow.

Author: Stebalien

tests/namedtempfile.rs

@@ -585,7 +585,8 @@ fn test_make_uds() {
     assert!(temp_sock.path().exists());
 }
 
-#[cfg(unix)]
+// This works(ish) on redox, but it's really slow.
+#[cfg(all(unix, not(target_os = "redox")))]
 #[test]
 fn test_make_uds_conflict() {
     use std::io::ErrorKind;