NetBSD: Skip tests on 9.x for network structs with alignment mismatches

These were previously packed, but this was changed in NetBSD10.

Link: NetBSD/src@1ca39e8

(backport <#4782>)
(cherry picked from commit 277c0c5)

Author: tgross35

libc-test/build.rs

@@ -1515,6 +1515,8 @@ fn test_netbsd(target: &str) {
 
         cfg.skip_struct(move |struct_| match struct_.ident() {
             x if x.starts_with("ptrace_lwp") => true,
+            // These were packed before NetBSD 10
+            "arphdr" | "in_addr" | "ip_mreq" | "sockaddr_in" => true,
             _ => false,
         });