chore(tests): remove flaky 10-turn travel-planning example test

[Aryansharma28]

Summary

• Removes `javascript/examples/vitest/tests/multiturn-10-scripted.test.ts`.
• The test runs ~21 sequential live LLM calls (10 user-sim + 10 assistant + 1 judge) under a 180s timeout.
• It has been timing out on CI for unrelated PRs (e.g. dependency-pin PRs like fix(security): patch path-to-regexp DoS via sequential optional groups #416 that don't touch the execution path).
• It's an example-suite test, not a correctness gate for the SDK.

Test plan

• CI green without this test.

[github-actions]

Automated low-risk assessment

This PR was evaluated against the repository's Low-Risk Pull Requests procedure.

• Scope: Deleted file javascript/examples/vitest/tests/multiturn-10-scripted.test.ts — removes a 10-turn travel-planning example test that performed ~21 sequential live LLM calls under a 180s timeout.
• Exclusions confirmed: no changes to auth, security settings, database schema, business-critical logic, or external integrations.
• Classification: low-risk-change under the documented policy.

This PR only deletes an example-suite test file that ran many live LLM calls; it does not modify authentication/authorization, secrets, database schemas, business logic, or production integrations. Removing a flaky test is a test-configuration/example change that is low risk and easy to revert if needed. CI behavior may change (fewer timeouts), but no runtime or security surface is affected by this diff.

This classification allows merging without manual review once all required CI checks are passing and branch protection rules are satisfied.