After https://github.com/zed-industries/zed/pull/3507, parsing the app's
semver version from the application plist stopped working, which caused
auto-updates to stop.

I don't think we need to put `-nightly` in the version number: it's
already in the release channel name, which is reported alongside the
version in most cases. For example, the 'About' dialog was saying `Zed
Nightly 2.0.0-nightly`.

I think even without nightly, it would be a good idea to include the
*release channel* name in the datadog alerts that show up in slack.
@JosephTLyons could you look into how to do that?

/cc @SomeoneToIgnore