Python code modernization, 3/n (#1157)

* Remove __metaclass__ = type.

for i in $(grep -REl '__metaclass__ = type' plugins/ tests/); do
  sed -e '/^__metaclass__ = type/d' -i $i;
done

* Remove super arguments, and stop inheriting from object.

plugins/module_utils/_api/transport/basehttpadapter.py

@@ -16,7 +16,7 @@ from .._import_helper import HTTPAdapter as _HTTPAdapter
 
 class BaseHTTPAdapter(_HTTPAdapter):
     def close(self):
-        super(BaseHTTPAdapter, self).close()
+        super().close()
         if hasattr(self, "pools"):
             self.pools.clear()