Tweak block-editor’s DimensionTool to avoid updating tests`

packages/block-editor/src/components/dimensions-tool/width-height-tool.js

@@ -60,13 +60,15 @@ export default function WidthHeightTool( {
 	const height = value.height === 'auto' ? '' : value.height ?? '';
 
 	const onDimensionChange = ( dimension ) => ( nextDimension ) => {
-		const nextValue = { ...value };
-		// Empty strings or undefined may be passed and both represent removing the value.
-		if ( ! nextDimension ) {
-			delete nextValue[ dimension ];
-		} else {
-			nextValue[ dimension ] = nextDimension;
-		}
+		// Readies the nextValue by omitting the dimension to be changed.
+		const { [ dimension ]: existingDimensionValue, ...nextValue } = value;
+		// Bails when both nextDimension and its existing value are falsy. This
+		// can occur when a `onDeselect` callback runs after the state has
+		// already updated. In such cases calling onChange would be redundant.
+		if ( ! nextDimension && ! existingDimensionValue ) return;
+
+		// Adds dimension only if non-falsy ('' or undefined may be passed).
+		if ( !! nextDimension ) nextValue[ dimension ] = nextDimension;
 		onChange( nextValue );
 	};