Please release version v5

[samuelcolvin]

Thanks so much for notify, it's great and I've had a really great experience wrapping it for the watchfiles python package.

Unfortunately, the continued use of pre-releases is making notify significantly harder to use than it should be.

Please could you release version 5.

In particular as per rust's dependency resolution logic on pre-releases:

Cargo allows "newer" pre-releases to be used automatically. For example, if 1.0.0-beta is published, then a requirement foo = "1.0.0-alpha" will allow updating to the beta version.

This means that we can't effectively lock the notify dependency to a specific pre-release.

As per samuelcolvin/watchfiles#144 and conda-forge/watchfiles-feedstock#5 this has just bitten us since conda forge decided to use 5.0.0-pre.15 which is incompatible with 5.0.0-pre.14 (which the package had been targeting) because PollWatcher::with_delay was replaced with PollWatcher::with_config. To make matters worse, this breaking change was not noted in the release notes.

[JohnTitor]

Duplicate of #249, please continue there.