Add autoflake to pre-commit configuration (#9666)

.pre-commit-config.yaml

@@ -20,6 +20,14 @@ repos:
     -   id: debug-statements
         exclude: _pytest/(debugging|hookspec).py
         language_version: python3
+-   repo: https://github.com/myint/autoflake
+    rev: v1.4
+    hooks:
+    -   id: autoflake
+        name: autoflake
+        args: ["--in-place", "--remove-unused-variables", "--remove-all-unused-imports"]
+        language: python
+        files: \.py$
 -   repo: https://github.com/PyCQA/flake8
     rev: 4.0.1
     hooks:

src/_pytest/python.py

@@ -905,8 +905,6 @@ class InstanceDummy:
     only to ignore it; this dummy class keeps them working. This will be removed
     in pytest 8."""
 
-    pass
-
 
 def __getattr__(name: str) -> object:
     if name == "Instance":

src/_pytest/python_api.py

@@ -131,7 +131,6 @@ class ApproxBase:
         # a numeric type.  For this reason, the default is to do nothing.  The
         # classes that deal with sequences should reimplement this method to
         # raise if there are any non-numeric elements in the sequence.
-        pass
 
 
 def _recursive_list_map(f, x):

testing/code/test_source.py

@@ -1,16 +1,13 @@
 # flake8: noqa
 # disable flake check on this file because some constructs are strange
 # or redundant on purpose and can't be disable on a line-by-line basis
-import ast
 import inspect
 import linecache
 import sys
 import textwrap
 from pathlib import Path
-from types import CodeType
 from typing import Any
 from typing import Dict
-from typing import Optional
 
 import pytest
 from _pytest._code import Code