feat(NODE-7212)!: upgrade macos deployment target to 11 (#99)

Author: baileympearson

binding.gyp

@@ -18,7 +18,7 @@
     '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' ],