bpo-32232: by default, Setup modules are no longer built with -DPy_BUILD_CORE (GH-6489)

Setup modules are no longer built with -DPy_BUILD_CORE by default,
as using that flag may now require including additional internal-only header files.

Instead, only the modules that specifically need it use that setting.
diff --git a/Modules/makesetup b/Modules/makesetup
index 31faf86..020b199 100755
--- a/Modules/makesetup
+++ b/Modules/makesetup
@@ -233,7 +233,7 @@
 			case $doconfig in
 			no)	cc="$cc \$(CCSHARED) \$(PY_CFLAGS) \$(PY_CPPFLAGS)";;
 			*)
-				cc="$cc \$(PY_CORE_CFLAGS)";;
+				cc="$cc \$(PY_STDMODULE_CFLAGS)";;
 			esac
 			rule="$obj: $src; $cc $cpps -c $src -o $obj"
 			echo "$rule" >>$rulesf