feat(NODE-7213)!: upgrade macos deployment target to 11 (#277)

Author: baileympearson

binding.gyp

@@ -16,7 +16,7 @@
       'xcode_settings': {
         'GCC_ENABLE_CPP_EXCEPTIONS': 'YES',
         'CLANG_CXX_LIBRARY': 'libc++',
-        'MACOSX_DEPLOYMENT_TARGET': '10.12',
+        'MACOSX_DEPLOYMENT_TARGET': '11',
         'GCC_SYMBOLS_PRIVATE_EXTERN': 'YES', # -fvisibility=hidden
       },
       'cflags!': [ '-fno-exceptions' ],