DOCS: Update README Development section with Xcode 16/Swift 6.0

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 89.40%. Comparing base (6e1fb3a) to head (04c8f9c). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #210 +/- ## ======================================= Coverage 89.40% 89.40% ======================================= Files 204 204 Lines 2860 2860 ======================================= Hits 2557 2557 Misses 303 303 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.