darwin: propagate build environment variables for Autotools (#28948)

GraphViz has failures due to overriding the default autoconf build
environment variables.

var/spack/repos/builtin/packages/graphviz/package.py

@@ -139,6 +139,9 @@ def autoreconf(self, spec, prefix):
         bash('./autogen.sh', 'NOCONFIG')
 
     def setup_build_environment(self, env):
+        # Set MACOSX_DEPLOYMENT_TARGET to 10.x due to old configure
+        super(Graphviz, self).setup_build_environment(env)
+
         if '+quartz' in self.spec:
             env.set('OBJC', self.compiler.cc)