add configuration to run all tests

src/frontend/playwright.config.ts

@@ -12,7 +12,7 @@ import { defineConfig, devices } from "@playwright/test";
 export default defineConfig({
   testDir: "./tests",
   /* Run tests in files in parallel */
-  fullyParallel: true,
+  fullyParallel: false,
   /* Fail the build on CI if you accidentally left test.only in the source code. */
   forbidOnly: !!process.env.CI,
   /* Retry on CI only */