FIX: use correct environ var

setup.py

@@ -11,7 +11,7 @@ class APIGenBuild(build_py):
         for version in build_versions:
             target_dir = os.path.join(self.build_lib, 'netdb_client', f"api{version.replace('.', '')}")
             self.mkpath(target_dir)
-            environ = os.environment.copy()
+            environ = os.environ.copy()
             environ['NETDB_VERSION'] = version
             gen = subprocess.run(['net-api-generator', 'python', f'--output-dir={target_dir}'], check=True, env=environ)
         build_py.run(self)