Always link with macOS frameworks but don't use -flat_namespace.
https://sourceforge.net/p/net-snmp/bugs/2634/
--- configure.orig	2023-08-15 15:32:24.000000000 -0500
+++ configure	2023-08-28 22:52:19.000000000 -0500
@@ -18348,38 +18348,9 @@
 	;;
 
     darwin*)
-        #   Flat Namespace linking                      (Mac OS/X)
+        #   Add frameworks                              (macOS)
         #
-        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether darwin ld might need -flat_namespace" >&5
-printf %s "checking whether darwin ld might need -flat_namespace... " >&6; }
-	if test -z "$MACOSX_DEPLOYMENT_TARGET"; then
-		saved_LDFLAGS="$LDFLAGS"
-                LDFLAGS="-flat_namespace -framework CoreFoundation -framework CoreServices -framework DiskArbitration -framework IOKit $LDFLAGS"
-                cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main (void)
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"
-then :
-  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-printf "%s\n" "yes" >&6; }
-else $as_nop
-  LDFLAGS="$saved_LDFLAGS"; { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
-printf "%s\n" "no" >&6; }
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.beam \
-    conftest$ac_exeext conftest.$ac_ext
-	else
-		{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
-printf "%s\n" "no" >&6; }
-	fi
+        LDFLAGS="-framework CoreFoundation -framework CoreServices -framework DiskArbitration -framework IOKit $LDFLAGS"
 	;;
 
     *)