Miri can set thread names now (#5108)

# Objective

rust-lang/miri#1717 has been fixed so we can set thread names in Miri now.

## Solution

We set thread names in Miri.

Author: RalfJung

crates/bevy_tasks/src/task_pool.rs

@@ -102,23 +102,12 @@ impl TaskPool {
                 let ex = Arc::clone(&executor);
                 let shutdown_rx = shutdown_rx.clone();
 
-                // miri does not support setting thread names
-                // TODO: change back when https://github.com/rust-lang/miri/issues/1717 is fixed
-                #[cfg(not(miri))]
-                let mut thread_builder = {
-                    let thread_name = if let Some(thread_name) = thread_name {
-                        format!("{} ({})", thread_name, i)
-                    } else {
-                        format!("TaskPool ({})", i)
-                    };
-                    thread::Builder::new().name(thread_name)
-                };
-                #[cfg(miri)]
-                let mut thread_builder = {
-                    let _ = i;
-                    let _ = thread_name;
-                    thread::Builder::new()
+                let thread_name = if let Some(thread_name) = thread_name {
+                    format!("{} ({})", thread_name, i)
+                } else {
+                    format!("TaskPool ({})", i)
                 };
+                let mut thread_builder = thread::Builder::new().name(thread_name);
 
                 if let Some(stack_size) = stack_size {
                     thread_builder = thread_builder.stack_size(stack_size);