Latest nightly fails to build for macos

Latest nightly builds fail to build for macos: https://nightlies.tbb.torproject.org/nightly-builds/tor-browser-builds/tbb-nightly.2024.04.21/nightly-macos/logs/firefox-macos-x86_64.log

 5:23.91 In file included from Unified_cpp_toolkit_xre0.cpp:110:
 5:23.92 /var/tmp/build/firefox-00e009df2d38/toolkit/xre/nsXREDirProvider.cpp:1329:26: error: use of undeclared identifier 'exists'
 5:23.92   rv = localDir->Exists(&exists);
 5:23.92                          ^

 5:23.93 /var/tmp/build/firefox-00e009df2d38/toolkit/xre/nsXREDirProvider.cpp:1331:8: error: use of undeclared identifier 'exists'; did you mean 'exit'?
 5:23.93   if (!exists) {
 5:23.93        ^~~~~~
 5:23.93        exit
 5:23.93 /var/tmp/dist/macosx-toolchain/MacOSX13.3.sdk/usr/include/stdlib.h:145:7: note: 'exit' declared here
 5:23.93 void     exit(int) __dead2;
 5:23.93          ^
 5:23.93 In file included from Unified_cpp_toolkit_xre0.cpp:110:
 5:23.93 /var/tmp/build/firefox-00e009df2d38/toolkit/xre/nsXREDirProvider.cpp:1331:8: warning: address of function 'exit' will always evaluate to 'true' [-Wpointer-bool-conversion]
 5:23.93   if (!exists) {
 5:23.93       ~^~~~~~
 5:23.93 /var/tmp/build/firefox-00e009df2d38/toolkit/xre/nsXREDirProvider.cpp:1331:8: note: prefix with the address-of operator to silence this warning
 5:23.93   if (!exists) {
 5:23.93        ^
 5:23.93        &