Migrate to Swift Testing from XCTest

[philippzagar]

Problem

With Swift Testing being added to the Swift 6 toolchain and the published images & Xcode already containing it, we should migrate all of our packages towards the modern Swift Testing framework.

Solution

All unit tests and should migrate from XCTest to the new Swift Testing framework included in the Swift 6 toolchain. We can follow the documentation article to migrating a test from XCTest.

Contributes working on this issue should first watch the swift-testing WWDC videos:

• Meet Swift Testing
• Go further with Swift Testing

We should take advantage of test suites, parameterized tests, and parallel testing and optimizing our test suites.

Code of Conduct

• I agree to follow this project's Code of Conduct and Contributing Guidelines