switch back to allow static mut refs

as dirs is breaking build

src/lib.rs

@@ -1,5 +1,5 @@
 #![warn(clippy::all, rust_2018_idioms)]
-#![cfg_attr(target_os = "linux", allow(static_mut_refs))] // dirs crate has warnings that break the CI build.
+#![allow(static_mut_refs)] // dirs crate has warnings that break the CI build.
 
 mod app;
 pub use app::MultinodeApp;