test(react-router): Pin react-router latest canary to v7

react-router 8 requires React 19; the SDK does not support v8 yet. Pin the latest-version E2E canary to the newest v7 release until v8 is supported.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: nicohrubec

dev-packages/e2e-tests/test-applications/react-router-7-framework/package.json

@@ -25,7 +25,7 @@
   },
   "scripts": {
     "build": "react-router build",
-    "test:build-latest": "pnpm install && pnpm add react-router@latest && pnpm add @react-router/node@latest && pnpm add @react-router/serve@latest && pnpm build",
+    "test:build-latest": "pnpm install && pnpm add react-router@7 && pnpm add @react-router/node@7 && pnpm add @react-router/serve@7 && pnpm build",
     "dev": "NODE_OPTIONS='--import ./instrument.mjs' react-router dev",
     "start": "NODE_OPTIONS='--import ./instrument.mjs' react-router-serve ./build/server/index.js",
     "proxy": "node start-event-proxy.mjs",