Ignore ruff error about EncodingWarning not defined in Python<3.10

We have a runtime guard right above it, so it is OK to ignore it.

Author: nicoddemus

testing/_py/test_local.py

@@ -19,7 +19,7 @@
 def ignore_encoding_warning():
     with warnings.catch_warnings():
         if sys.version_info > (3, 10):
-            warnings.simplefilter("ignore", EncodingWarning)
+            warnings.simplefilter("ignore", EncodingWarning)  # noqa: F821
         yield