[used-before-assignment] False positive for "same test" exception when test is a walrus operator

[jacobtylerwalls]

Primer run on #10034 exposed a false positive we can address separately:

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Effect on home-assistant:
The following messages are now emitted:

1. possibly-used-before-assignment:
   Possibly using variable 'touch_event_callback' before assignment
   https://github.com/home-assistant/core/blob/b09e54c961db279785b75b5c3d192624b3d65664/homeassistant/components/nanoleaf/__init__.py#L77

This comment was generated for commit d7ddc89

Originally posted by @github-actions[bot] in #10034 (comment)