Remove unused struct

Author: mu001999

library/std/src/sys/pal/unsupported/net.rs

@@ -364,7 +364,4 @@ pub mod netc {
         pub sin6_flowinfo: u32,
         pub sin6_scope_id: u32,
     }
-
-    #[derive(Copy, Clone)]
-    pub struct sockaddr {}
 }