fix: TreeGrid children not showing after quick expand/collapse (24.9) [0.5 days]

[mcollovati]

When a TreeGrid node was expanded and then collapsed before data arrived from a slow data provider, subsequent expansion attempts would show no children. This was caused by the grid's sub-cache retaining a size of 0 from the cancelled request.

The fix removes the sub-cache when collapsing an item with pending requests, allowing fresh data to be fetched on re-expand.

Fixes vaadin/flow#21731

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[sonarqubecloud[bot]]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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[vaadin-bot]

This ticket/PR has been released with Vaadin 24.9.11.