Fix target triple on macOS

With the release of Xcode 15, a new linker was introduced and with it
came warnings from the linker. It appears that the new linker is
stricter in which target triples it considers valid. Specifically, it
looks like the minimum deployment target is required. E.g.,
`aarch64-apple-darwin23.3.0` is valid, while `aarch64-apple-darwin` is
not.

See also:

* https://developer.apple.com/documentation/xcode-release-notes/xcode-15-release-notes#Linking
* crystal-lang/crystal#13846

omnibus/config/software/crystal.rb

@@ -68,14 +68,12 @@
   mkdir ".build"
   copy "#{output_bin}_x86_64", ".build/crystal"
 
-  # Compile for ARM64. Apple's clang only understands arm64, LLVM uses aarch64,
-  # so we need to sub out aarch64 in our calls to Apple tools
-  env["CXXFLAGS"] << " -target arm64-apple-darwin"
   make "deps", env: env
 
-  make "crystal stats=true release=true target=aarch64-apple-darwin FLAGS=\"#{crflags}\" CRYSTAL_CONFIG_TARGET=aarch64-apple-darwin CRYSTAL_CONFIG_LIBRARY_PATH= O=#{output_path}", env: env
+  crtarget = "arm64-apple-macosx#{ENV["MACOSX_DEPLOYMENT_TARGET"]}"
+  make "crystal stats=true release=true target=#{crtarget} FLAGS=\"#{crflags}\" CRYSTAL_CONFIG_TARGET=#{crtarget} CRYSTAL_CONFIG_LIBRARY_PATH= O=#{output_path}", env: env
 
-  command "clang #{output_path}/crystal.o -o #{output_bin}_arm64 -target arm64-apple-darwin src/llvm/ext/llvm_ext.o `llvm-config --libs --system-libs --ldflags 2>/dev/null` -lstdc++ -lpcre2-8 -lgc -lpthread -levent -liconv -ldl -v", env: env
+  command "clang #{output_path}/crystal.o -o #{output_bin}_arm64 -target #{crtarget} src/llvm/ext/llvm_ext.o `llvm-config --libs --system-libs --ldflags 2>/dev/null` -lstdc++ -lpcre2-8 -lgc -lpthread -levent -liconv -ldl -v", env: env
   delete "#{output_path}/crystal.o"
 
   # Lipo them up

omnibus/config/software/shards.rb

@@ -96,9 +96,10 @@
   make "clean", env: env
 
   # Build for ARM64
-  crflags += " --cross-compile --target aarch64-apple-darwin"
+  crtarget = "arm64-apple-macosx#{ENV["MACOSX_DEPLOYMENT_TARGET"]}"
+  crflags += " --cross-compile --target #{crtarget}"
   make "bin/shards SHARDS=false CRYSTAL=#{install_dir}/bin/crystal FLAGS='#{crflags}'", env: env
-  command "clang bin/shards.o -o bin/shards_arm64 -target arm64-apple-darwin -L#{install_dir}/embedded/lib -lyaml -lpcre2-8 -lgc -lpthread -levent -liconv -ldl", env: env
+  command "clang bin/shards.o -o bin/shards_arm64 -target #{crtarget} -L#{install_dir}/embedded/lib -lyaml -lpcre2-8 -lgc -lpthread -levent -liconv -ldl", env: env
 
   # Lipo them up
   command "lipo -create -output bin/shards bin/shards_x86_64 bin/shards_arm64"