lint: run autoflake on webdriver/ (#43097)

diff --git a/webdriver/tests/bidi/browsing_context/navigation_started/navigation_started.py b/webdriver/tests/bidi/browsing_context/navigation_started/navigation_started.py
index 448f96e..069292b 100644
--- a/webdriver/tests/bidi/browsing_context/navigation_started/navigation_started.py
+++ b/webdriver/tests/bidi/browsing_context/navigation_started/navigation_started.py
@@ -1,4 +1,3 @@
-import asyncio
 
 import pytest
 from tests.support.sync import AsyncPoll
diff --git a/webdriver/tests/bidi/browsing_context/user_prompt_closed/user_prompt_closed.py b/webdriver/tests/bidi/browsing_context/user_prompt_closed/user_prompt_closed.py
index ffbdcec..fabf511 100644
--- a/webdriver/tests/bidi/browsing_context/user_prompt_closed/user_prompt_closed.py
+++ b/webdriver/tests/bidi/browsing_context/user_prompt_closed/user_prompt_closed.py
@@ -1,4 +1,3 @@
-import asyncio
 import pytest
 from tests.support.sync import AsyncPoll
 from webdriver.error import TimeoutException
diff --git a/webdriver/tests/bidi/network/add_intercept/phase_auth_required.py b/webdriver/tests/bidi/network/add_intercept/phase_auth_required.py
index fb539bf..d6ea0a2 100644
--- a/webdriver/tests/bidi/network/add_intercept/phase_auth_required.py
+++ b/webdriver/tests/bidi/network/add_intercept/phase_auth_required.py
@@ -1,4 +1,3 @@
-import asyncio
 
 import pytest
 from webdriver.bidi.modules.script import ScriptEvaluateResultException
diff --git a/webdriver/tests/bidi/network/add_intercept/phases.py b/webdriver/tests/bidi/network/add_intercept/phases.py
index c6fba72..4b244c9 100644
--- a/webdriver/tests/bidi/network/add_intercept/phases.py
+++ b/webdriver/tests/bidi/network/add_intercept/phases.py
@@ -1,4 +1,3 @@
-import asyncio
 
 import pytest
 from webdriver.bidi.modules.script import ScriptEvaluateResultException
diff --git a/webdriver/tests/classic/execute_async_script/objects.py b/webdriver/tests/classic/execute_async_script/objects.py
index edcf065..2957429 100644
--- a/webdriver/tests/classic/execute_async_script/objects.py
+++ b/webdriver/tests/classic/execute_async_script/objects.py
@@ -46,4 +46,4 @@
             }
         });
         """)
-    value = assert_error(response, "javascript error")
+    assert_error(response, "javascript error")
diff --git a/webdriver/tests/classic/execute_script/objects.py b/webdriver/tests/classic/execute_script/objects.py
index e254fe2..6447bce 100644
--- a/webdriver/tests/classic/execute_script/objects.py
+++ b/webdriver/tests/classic/execute_script/objects.py
@@ -46,4 +46,4 @@
             }
         };
         """)
-    value = assert_error(response, "javascript error")
+    assert_error(response, "javascript error")