Update CI to use Xcode 14 beta 6 (#4125)
Update CI to use Xcode 14 beta 6 (#4125)

Only used for the TSan CI job right now, which was previously using
Xcode 14 beta 5.

https://twitter.com/XcodeReleases/status/1562130365191315457
realm/SwiftLint,realm/SwiftLint,realm/SwiftLint,realm/SwiftLint