[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

testing/test_tracer.py

@@ -2,7 +2,9 @@
 
 import pytest
 
-from pluggy import PluginManager, HookspecMarker, HookimplMarker
+from pluggy import HookimplMarker
+from pluggy import HookspecMarker
+from pluggy import PluginManager
 from pluggy._tracing import TagTracer
 
 hookspec = HookspecMarker("example")