test(node): Use random port in hono tracing scenario to avoid CI flakes

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Summary

Fixes the flaky suites/tracing/hono/test.ts Node integration test (should handle transactions for all route/method/path combinations).

Root cause

The Hono tracing scenario binds its server to a hardcoded port 8787:

const port = 8787;
serve({ fetch: app.fetch, port });
sendPortToRunner(port);

The integration-test runner explicitly warns against this — a fixed port is fine for local debugging but "dangerous for CI/CD environments where port collisions can cause flakes". When port 8787 is already in use (e.g. a not-yet-fully-killed child process from a prior run, or another concurrent suite), @hono/node-server fails to bind, the scenario never serves requests on a usable socket, and the runner times out waiting for transactions — surfacing as an intermittent failure.

The sibling suites/hono-sdk/scenario.mjs already uses the correct pattern: bind to port 0 (OS-assigned free port) and report the actually-bound port back to the runner via the serve callback. This change mirrors that:

serve({ fetch: app.fetch, port: 0 }, info => {
  sendPortToRunner(info.port);
});

Test behavior and assertions are unchanged — only the port allocation strategy is fixed, eliminating the collision window.

Fixes #21174