Small patch to support Xcode 15 (#292) and minor improvements to the regression test pipeline.

What's Changed

• Use canImport for MLTensor checks by @ZachNagengast in https://github.com/argmaxinc/WhisperKit/pull/288
• Add repo option to regression test matrix by @ZachNagengast in https://github.com/argmaxinc/WhisperKit/pull/293

Full Changelog: https://github.com/argmaxinc/WhisperKit/compare/v0.10.1...v0.10.2