Bug: build is broken on FreeBSD if libsysinfo is installed

FreeBSD has a libsysinfo package which contains GNU libc's sysinfo port. 
  Some users reported git 2.50.0 was failing to build when this port is 
installed and it happened because configure script detected libsysinfo 
but -lsysinfo was not added to LDFLAGS, ending up with following error:

scalar.o common-main.o libgit.a xdiff/lib.a reftable/libreftable.a libgit.a -lz -pthread ld: error: undefined symbol: sysinfo

This patch [1] was added to git port adding a user option to enable/disable libsysinfo dependency and fix LDFLAGS when it's enabled.

I'm not sure about what is best approach for git project in this case.

[1] https://github.com/freebsd/freebsd-ports/blob/main/devel/git/files/patch-configure.ac