ci: fix web test timeouts and hangs

[walles]

This PR fixes two separate issues that caused the CI pipeline to hang indefinitely during the web tests:

1. Browser Launch Hang: Playwright couldn't find the necessary OS dependencies to run a headless browser on the Ubuntu runners. Fixed by adding `--with-deps` to the `npx playwright install` step.
2. Post-Test Shutdown Hang: A known bug in `@vscode/test-web` prevented the test runner from shutting down cleanly because it was looking for a missing localization file. Fixed by creating an empty `package.nls.json` and bumping the test runner version.

This should unblock all other PRs.