chore: lock the plugin boundary and remove 2.9.0 leftovers

plugins/tailscale/tests/frontend/TailscaleDevicesPanel.test.tsx

@@ -8,7 +8,8 @@ vi.mock("../../src/frontend/tailscale-api", () => ({
   getTailscaleDevices: getTailscaleDevicesMock,
 }));
 
-vi.mock("react-i18next", () => ({
+vi.mock("react-i18next", async (importOriginal) => ({
+  ...(await importOriginal<object>()),
   useTranslation: () => ({ t: (key: string) => key }),
 }));