- `#[once]` fixtures now require the returned type to be

[`Sync`](https://doc.rust-lang.org/std/marker/trait.Sync.html) to prevent UB

when tests are executed in parallel. (see [#235](https://github.com/la10736/rstest/issues/235)

for more details)

- `#[future(awt)]` and `#[awt]` now properly handle mutable (`mut`) parameters by treating futures as immutable and

treating the awaited rebinding as mutable.