Add a 'Minimal Mach-O arm64' build preset on top of the existing x86_64 one (#61831)

Author: kubamracek

utils/build-presets.ini

@@ -2579,6 +2579,18 @@ mixin-preset=stdlib_S_standalone_minimal_macho_x86_64,build
 test
 validation-test
 
+[preset: stdlib_S_standalone_minimal_macho_arm64,build]
+mixin-preset=stdlib_S_standalone_minimal_macho_x86_64,build
+stdlib-deployment-targets=freestanding-arm64
+swift-primary-variant-arch=arm64
+swift-freestanding-archs=arm64
+
+[preset: stdlib_S_standalone_minimal_macho_arm64,build,test]
+mixin-preset=stdlib_S_standalone_minimal_macho_arm64,build
+
+test
+validation-test
+
 [preset: stdlib_S_standalone_darwin_x86_64,build]
 mixin-preset=
     stdlib_S_standalone,build