chore: update cpal to latest Git, fix conflict

[philpax]

This PR is a prospective update of the cpal dependency to the latest Git version. It is not intended to be merged (at least until the next cpal release is cut); instead, it's intended as a version of rodio that can have its cpal patched with a fork of the ~current cpal HEAD (e.g. my RustAudio/cpal#1027).

The only changes so far:

• running cargo update -p objc2 to break a dependency resolution conflict
• replacing From<Input> for cpal::Device with Input::into_inner, as cpal now has a conflicting trait implementation. I considered implementing Into, but the asymmetry of not having the From is generally frowned upon. (the From blanket impl blocks this)
• enables U24 support
• removes the cpal-shared-stdcxx feature, which activates the oboe backend for cpal, which has since been removed

[roderickvd]

Thanks for this preparatory work. Now that RustAudio/cpal#1011 is merged, we can also enable the U24 sample format in stream.rs and microphone.rs.

[philpax]

Done and updated to the latest cpal 🙂