AnimationControlled must be disposed

[pMertDogan]

_MapBoxPlaceSearchWidgetState created a Ticker via its SingleTickerProviderStateMixin, but at the time dispose() was called on the mixin, that Ticker was still active. The Ticker must be disposed before calling super.dispose().

Tickers used by AnimationControllers should be disposed by calling dispose() on the AnimationController itself. Otherwise, the ticker will leak.