Drop useless use of abc.ABCMeta

Author: philpep

testinfra/modules/base.py

@@ -9,11 +9,10 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-import abc
 import typing
 
 
-class Module(metaclass=abc.ABCMeta):
+class Module:
     if typing.TYPE_CHECKING:
         import testinfra.host