Binary distributions might not be compatible with macOS <10.13

Currently we set MACOSX_DEPLOYMENT_TARGET=10.10 when building binary distributions. We also explicitly disable ac_cv_func_clock_gettime (see #12858 (closed)) and ac_cv_func_utimensat (#17895 (closed)). Together, these measures are supposed to guarantee compatibility with all macOS releases 10.10 and later.

However, while working on enabling more C compiler warnings in !9579 (closed) I found that the x86-64/Darwin build reported the following:

===> Command failed with error code: 1
/var/folders/40/9ycf5rrj1mq89k2xdpyt5rl00000hm/T/ghc51748_0/ghc_2.c:14:113: error:
     error: 'futimens' is only available on macOS 10.13 or newer [-Werror,-Wunguarded-availability-new]
   |
14 | HsInt32 ghczuwrapperZC3ZCunixzm2zi8zi0zi0ZCSystemziPosixziFilesziCommonZCfutimens(HsInt32 a1, void* a2) {return futimens(a1, a2);}
   |                                                                                                                 ^
HsInt32 ghczuwrapperZC3ZCunixzm2zi8zi0zi0ZCSystemziPosixziFilesziCommonZCfutimens(HsInt32 a1, void* a2) {return futimens(a1, a2);}

This suggests that we also need to disable ac_cv_func_futimens (and potentially others).