Remove outdated cfg on le32

See rust-lang#45041 for the removal of the
target (le32-unknown-nacl).

Author: Urgau

library/std/src/os/linux/raw.rs

@@ -26,7 +26,6 @@ pub use self::arch::{blkcnt_t, blksize_t, ino_t, nlink_t, off_t, stat, time_t};
 
 #[cfg(any(
     target_arch = "x86",
-    target_arch = "le32",
     target_arch = "m68k",
     target_arch = "powerpc",
     target_arch = "sparc",