bindings/python: Use GILProtected instead to Mutex

[Xuanwo]

          We might be able to use [`GILProtected`](https://docs.rs/pyo3/0.19.2/pyo3/sync/struct.GILProtected.html) instead of `Mutex` here  since python object access is already synchronized with Python GIL.

Originally posted by @messense in #3474 (comment)

[Justin-Xiang]

@Xuanwo Hi, I'd like to do this job.

[Xuanwo]

@Xuanwo Hi, I'd like to do this job.

Welcome!

[Xuanwo]

Hi, @Justin-Xiang, you can post your questions here. @messense is one of the committers of pyo3.

[Justin-Xiang]

Thank You! @Xuanwo
Hi, @messense , I'm Justin, I'm trying to replace Mutex with GILProtected.
take fn close for example, I can change state this way based on the GILProtected document.

pub struct GILFile(Ars GILProtected‹GILFileState>>);
enum GILFileState{
Reader(ocore::Reader),
Writer(ocore::Writer),
Closed,
}
impl GILFile{
fn close<'p>(&'p mut self, py: Python<'p>) -> PyResult<()> {
        Python::with_gil(|py| {
            let mut state = self.0.get(py);
            *state.borrow_mut() = &GILFileState::Closed;
        });
        Ok(())
    }
}

But I don't know how to convert this to future, I can't put them in the async move function body
Anyone else who knows how to deal with it can make a PR though I'm the assignee.

[messense]

@Justin-Xiang Could you open a draft PR with what you have written so far?

[Justin-Xiang]

unassign me since I'm focusing on the tests part right now

[hanxuanliang]

Can I have a try? Recently learning some usage of PyO3, want to try to contribute

[Xuanwo]

Can I have a try? Recently learning some usage of PyO3, want to try to contribute

Thanks a lot!