Don't ignore setup.py even if a setup.cfg file exists

Even if using a setup.cfg, you need a setup.py to pull in its data, and that setup.py may have additional data in it which we were previously ignoring

Author: rotu

colcon_ros/package_identification/ros.py

@@ -9,7 +9,6 @@
 from colcon_core.package_identification import logger
 from colcon_core.package_identification \
     import PackageIdentificationExtensionPoint
-from colcon_core.package_identification.python import get_configuration
 from colcon_core.plugin_system import satisfies_version
 from colcon_core.plugin_system import SkipExtensionException
 from colcon_python_setup_py.package_identification.python_setup_py \
@@ -102,28 +101,12 @@ def identify(self, desc):  # noqa: D102
                 desc.dependencies['test'].add(DependencyDescriptor(
                     d.name, metadata=_create_metadata(d)))
 
-        # for Python build types ensure that a setup.py file exists
         if build_type == 'ament_python':
-            setup_cfg = desc.path / 'setup.cfg'
-            for _ in (1, ):
-                # try to get information from setup.cfg file
-                if setup_cfg.is_file():
-                    config = get_configuration(setup_cfg)
-                    name = config.get('metadata', {}).get('name')
-                    if name:
-                        options = config.get('options', {})
-
-                        def getter(env):
-                            nonlocal options
-                            return options
-                        break
-            else:
-                # use information from setup.py file
-
-                def getter(env):  # noqa: F811
-                    nonlocal desc
-                    return get_setup_arguments_with_context(
-                        str(desc.path / 'setup.py'), env)
+            # use information from setup.py file
+            def getter(env):  # noqa: F811
+                nonlocal desc
+                return get_setup_arguments_with_context(
+                    str(desc.path / 'setup.py'), env)
 
             desc.metadata['get_python_setup_options'] = getter