Rollup merge of #126632 - Vonr:fix/moving-closure-formatting-v2, r=Nilstrieb

Replace `move||` with `move ||`

Edit from #126631 to revert changes in `tests/ui`.

There are 18 instances of `move||` across 6 files in the repo:
- `compiler/rustc_hir_typeck/src/typeck_root_ctxt.rs`
- `library/core/src/sync/atomic.rs`
- `library/std/src/sync/condvar.rs`
- `library/std/src/sync/mpsc/mod.rs`
- `library/std/src/sync/barrier.rs`
- `library/std/src/thread/local.rs`

I have replaced all such instances with `move ||` instead as it better adheres to modern formatting standards.

Ideally, we would have this automated by rustfmt or some other tool, but I do not have the time to implement such a feature or tool.
Nonetheless, I would encourage any effort invested into such a tool or feature.

compiler/rustc_hir_typeck/src/typeck_root_ctxt.rs

@@ -22,7 +22,7 @@ use std::ops::Deref;
 /// e.g. closures defined within the function. For example:
 /// ```ignore (illustrative)
 /// fn foo() {
-///     bar(move|| { ... })
+///     bar(move || { ... })
 /// }
 /// ```
 /// Here, the function `foo()` and the closure passed to