Merge pull request swiftlang#78787 from bnbarham/cherry-build-testing

[6.1] Build swift-testing as part of the compat-suite toolchain

Author: bnbarham

utils/build-presets.ini

@@ -2944,13 +2944,17 @@ build-ninja
 llbuild
 swiftpm
 swift-driver
+swift-testing
+swift-testing-macros
 install-llbuild
 install-llvm
 install-static-linux-config
 install-swift
 install-swiftpm
 install-swift-driver
 install-swiftsyntax
+install-swift-testing
+install-swift-testing-macros
 reconfigure
 verbose-build
 skip-build-benchmarks