chore: roll stable-test-runner to: 1.50.0-beta-1737557690000 (#34433)

Author: agg23

tests/playwright-test/stable-test-runner/package-lock.json

@@ -1,6 +1,6 @@
 {
   "private": true,
   "dependencies": {
-    "@playwright/test": "1.50.0-alpha-2025-01-17"
+    "@playwright/test": "1.50.0-beta-1737557690000"
   }
 }