scripts/javascript/screenshots: promote ValidatorLightweightPicker golden

CI run 25687411993 on 2fd58aa produced a fresh
ValidatorLightweightPicker render that didn't show up in the prior
run's artifacts (the test emits a Form-screenshot only when the picker
flyout is the topmost layer at sample time, which is timing-sensitive).
Compare classifies it ``different`` because the existing golden was
captured at 2x DPI (750x1334) while the rest of the goldens and the
new run are at 1x (375x667). Visual content is identical -- promote
the 1x render so the dimension delta no longer fails the suite.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: shai-almog