test(e2e): Add @playwright/test to nuxt-sourcemaps app

The e2e workflow's Playwright setup runs for every test app and fails
with exit 127 when the app cannot resolve @playwright/test, even for
build-only apps that never launch a browser. react-router-sourcemaps
carries the dependency for the same reason.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: JPeer264

dev-packages/e2e-tests/test-applications/nuxt-sourcemaps/package.json

@@ -13,6 +13,7 @@
     "nuxt": "^4.1.2"
   },
   "devDependencies": {
+    "@playwright/test": "~1.56.0",
     "@sentry-internal/test-utils": "link:../../../test-utils",
     "tsx": "^4.23.0",
     "typescript": "^5.6.3"