[CCUBE-2268][GZ] wait for filter checkbox item animation

[ghazwan-gt]

Type of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing apis or functionality to change)
• Documentation (change to documentation, comments or API descriptions)
• Tests (improvements to unit tests or E2E tests)
• Other (technical improvements, refactoring, or changes that don't fall into the above categories)

Description of changes

• Link to ticket

The FilterItem component uses react-spring to animate expandable container height based on useResizeDetector. On mount in mobile mode, a cascade occurs. The current waitForAnimationEnd can pass before the cascade finishes. When this happens, the screenshot captures a mid-animation state, producing the pixel diffs.

The fix is to wait until the cascades flushed, then recheck the element stability.

Checklist

• Changes follow the project guidelines in CONTRIBUTING.md and CONVENTIONS.md
• Looks good on mobile and tablet
• Updated documentation
• Added/updated unit tests
• Added/updated E2E tests

Screenshots