Finalize multi-select support for custom tree view

Fixes #76941

src/vs/vscode.d.ts

@@ -6882,6 +6882,13 @@ declare module 'vscode' {
 		 * Whether to show collapse all action or not.
 		 */
 		showCollapseAll?: boolean;
+
+		/**
+		 * Whether the tree supports multi-select. When the tree supports multi-select and a command is executed from the tree,
+		 * the first argument to the command is the tree item that the command was executed on and the second argument is an
+		 * array containing the other selected tree items.
+		 */
+		canSelectMany?: boolean;
 	}
 
 	/**

src/vs/vscode.proposed.d.ts

@@ -1030,15 +1030,6 @@ declare module 'vscode' {
 		 */
 		constructor(label: TreeItemLabel, collapsibleState?: TreeItemCollapsibleState);
 	}
-
-	export interface TreeViewOptions2<T> extends TreeViewOptions<T> {
-		/**
-		 * Whether the tree supports multi-select. When the tree supports multi-select and a command is executed from the tree,
-		 * the first argument to the command is the tree item that the command was executed on and the second argument is an
-		 * array containing the other selected tree items.
-		 */
-		canSelectMany?: boolean;
-	}
 	//#endregion
 
 	//#region CustomExecution

src/vs/workbench/api/common/extHostTreeViews.ts

@@ -193,7 +193,7 @@ class ExtHostTreeView<T> extends Disposable {
 	private refreshPromise: Promise<void> = Promise.resolve();
 	private refreshQueue: Promise<void> = Promise.resolve();
 
-	constructor(private viewId: string, options: vscode.TreeViewOptions2<T>, private proxy: MainThreadTreeViewsShape, private commands: CommandsConverter, private logService: ILogService, private extension: IExtensionDescription) {
+	constructor(private viewId: string, options: vscode.TreeViewOptions<T>, private proxy: MainThreadTreeViewsShape, private commands: CommandsConverter, private logService: ILogService, private extension: IExtensionDescription) {
 		super();
 		this.dataProvider = options.treeDataProvider;
 		this.proxy.$registerTreeViewDataProvider(viewId, { showCollapseAll: !!options.showCollapseAll, canSelectMany: !!options.canSelectMany });