Add override keyword in codebase (#120755)

For #120675

This uses a script to add the override keyword to places that need it in the codebase

Note that we can't enable the --noImplicitOverride setting yet since there are still around 200 errors that require further attention

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

@@ -1007,7 +1007,7 @@ export class NotebookCellStatusBarItemInternal extends Disposable {
 		this.update();
 	}
 
-	dispose(): void {
+	override dispose(): void {
 		this.hide();
 		this._isDisposed = true;
 		this._internalCommandRegistration.dispose();