[6.2] preset: treat swift testing the same as xctest

[bkhouri]

Whenever XCtest is build and installed, do the same for swift-testing and swift-testing macros.

(cherry picked from commit 2962ea2)

Based on #81401

Explanation:
The SwiftPM repository added Swift Testing helpers in a non-test target, so we can re-used common helpers (e.g.: custom traits, custom tags, etc...). As part of the toolchain build, SwiftPM builds a baseline of itself using Cmake, then build the Package.swift using the Cmake artifact. During the "second" stage SwiftPM build, this non-test target (which is meant to only be used by tests), will be complied, and would cause a "Testing module not found error".

The ideal solution would be to have a SwiftPM feature that would allow the specifying targets to only be made available for test target. Converting this target to a test targets causes swift build and swift test to succeed, but Xcode package resolution fails.

The path to least resistance was to treat Swift Testing, and Swift Testing Macros the same as XCTest in the build presets.

Scope:
This will likely cause longe build times since additional "projects" may be built.

Issues:
N/A

Original PRs:
#81401, to allow swiftlang/swift-package-manager#8495 and swiftlang/swift-package-manager#8663, and other changes to https://github.com/swiftlang/swift-package-manager Swift Testing tests.

Risk:
this is low risk as the change build extra "projects", but toolchain builds will likely fail if this is merged after the next SwiftPM main to release/6.2 merge

Testing:
If we can get a toolchain successfully built, this would yield positive results. and prefer have this merged before the next SwiftPM main to release/6.2 merge to avoid toolchain build failures.

Reviewers:
@etcwilde

[bkhouri]

@swift-ci smoke test

[bkhouri]

@swift-ci test