Upgrade XCode and remove mapbox certificate build script

[f1sh1918]

Is your feature request related to a problem? Please describe. We should upgrade the XCode versions in the CI to a newer version and also switch to that version in local builds as well. XCode 15.0.1 has an issue with mapbox certificates, therefore as a workaround there was a shell script added to manually remove old certificates.

Describe the solution you'd like

• [ ] XCode images used in CircleCI should be upgraded.
• [ ] Notify other team members using XCode to upgrade their versions as well
• [ ] This script should be removed with a new XCode or Mapbox version that fixes that issue

Describe alternatives you've considered None.

Additional context How to add/remove build scripts https://developer.apple.com/documentation/xcode/running-custom-scripts-during-a-build

Upstream issue: https://github.com/CocoaPods/CocoaPods/issues/12022

Workaround done in #2557. Slightly related to #2813 (upgrading xcode).

[ztefanie]

See here: https://github.com/CocoaPods/CocoaPods/issues/12022

[steffenkleinle]

@ztefanie @f1sh1918 I upgraded to XCode v15.3.0 in #2772, so probably you should upgrade your locally installed version as well. Since the mapbox certificate build script is still necessary, I'll move this to the backlog again.