chore(dev-deps): downgrade playwright

[AriPerkkio]

• Downgrade playwright to avoid [Browser Mode]: flaky firefox Failed to connect to the browser session vitest-dev/vitest#7377

See https://github.com/stackblitz/webcontainer-test/actions/runs/14488808706/job/40641216025

⎯⎯⎯⎯⎯⎯ Unhandled Error ⎯⎯⎯⎯⎯⎯⎯
Error: Failed to connect to the browser session "243e2a75-c500-403e-83c9-66b04a7f1164" [Firefox] for "test/mount.test.ts", "test/file-system.test.ts" within the timeout.
 ❯ Timeout._onTimeout node_modules/.pnpm/vitest@3.1.1_@types+node@22.14.0_@vitest+browser@3.1.1/node_modules/vitest/dist/chunks/cli-api.bwYuoT4p.js:5263:17
 ❯ listOnTimeout node:internal/timers:594:17
 ❯ process.processTimers node:internal/timers:529:7