Xcode 14 merges the WKExtension target into the WKApplication target and it seems (as of 14.3/9.4 SDK at least) that the availability check now fails when used as part of one of these projects.

[Danny19828991]

Xcode 14 merges the WKExtension target into the WKApplication target and it seems (as of 14.3/9.4 SDK at least) that the availability check now fails when used as part of one of these projects.

This PR adds a watchOS availability check to fix this.

Originally posted by @pixlwave in #11