Birthday Demo is not compatible with Swift 6

[bastiW]

Describe the bug
The Birthday Demo is not compatible with Swift 6 Demo

To Reproduce
Checkout the Birthday Example.
Go to Build Settings
Swift - Compiler Language
Change Swift Language Version to: Swift 6
Compile it

Expected behavior
Should compile

[w-goog]

This should now work :) Thanks for reporting! Give it a go, and let us know if you run into any issues.