threadleak_ignored should now pass with preemption (the issue has been fixed a while ago)

Author: RalfJung

src/tools/miri/tests/pass/threadleak_ignored.rs

@@ -1,5 +1,4 @@
-// FIXME: disallow preemption to work around https://github.com/rust-lang/rust/issues/55005
-//@compile-flags: -Zmiri-ignore-leaks -Zmiri-preemption-rate=0
+//@compile-flags: -Zmiri-ignore-leaks
 
 //! Test that leaking threads works, and that their destructors are not executed.