fix(bindings/python): missed to call close for the file internally

[zzl221000]

close writer
fixes #4120

[Xuanwo]

clippy is the rust lint that help us write better code, for example:

error: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let`
   --> bindings/python/src/file.rs:399:13
    |
399 | /             match &mut *state {
400 | |                 AsyncFileState::Writer(w) => {
401 | |                     w.close()
402 | |                         .await
...   |
405 | |                 _ => {}
406 | |             }
    | |_____________^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_match
help: try
    |
399 ~             if let AsyncFileState::Writer(w) = &mut *state {
400 +                 w.close()
401 +                     .await
402 +                     .map_err(|err| PyIOError::new_err(err.to_string()))?;
403 +             }

[Xuanwo]

Hi, @messense @Zheaoli is there a way for use to return error during exist context manager?

[Xuanwo]

Thanks!

[Xuanwo]

We need to fix some edge cases, but this PR seems to be an improvement to the current codebase. Let's merge it first!