Disable mod sys/resource on Solaris

Looks like Solaris does not have them according to our CI [1]

[1]: https://github.com/nix-rust/nix/actions/runs/19349070659/job/55356544189?pr=2694

Author: SteveLauC

src/sys/mod.rs

@@ -96,6 +96,7 @@ feature! {
 #[cfg(not(any(
     target_os = "redox",
     target_os = "fuchsia",
+    target_os = "solaris",
     target_os = "haiku"
 )))]
 feature! {