Close Model Alerts view when Model editor closes (#3468)

Author: charisk

extensions/ql-vscode/src/model-editor/model-alerts/model-alerts-view.ts

@@ -87,5 +87,13 @@ export class ModelAlertsView extends AbstractWebview<
         }
       }),
     );
+
+    this.push(
+      this.modelingEvents.onDbClosed(async (event) => {
+        if (event === this.dbItem.databaseUri.toString()) {
+          this.dispose();
+        }
+      }),
+    );
   }
 }