fixup feature position in liballoc

Author: Gankra

library/alloc/src/lib.rs

@@ -127,6 +127,7 @@
 #![feature(slice_ptr_len)]
 #![feature(slice_range)]
 #![feature(str_internals)]
+#![feature(strict_provenance)]
 #![feature(trusted_len)]
 #![feature(trusted_random_access)]
 #![feature(try_trait_v2)]
@@ -158,7 +159,6 @@
 #![feature(rustc_allow_const_fn_unstable)]
 #![feature(rustc_attrs)]
 #![feature(staged_api)]
-#![feature(strict_provenance)]
 #![cfg_attr(test, feature(test))]
 #![feature(unboxed_closures)]
 #![feature(unsized_fn_params)]