fix(snapshot): skip notFound and onError handlers of Hono v5

[yusukebe]

On Hono v5, inspectRoutes lists notFound and onError handlers with methods like @NOT_FOUND and @ERROR. snapshot printed them as lines, so piping its output into hono batch failed with "'@NOT_FOUND' is not a valid HTTP method". Found on a v5 app with app.notFound(). Now snapshot skips them; the probe line still records the not-found response.

The author should do the following, if applicable

• Add tests
• Run tests
• pnpm run format:fix && pnpm run lint:fix to format the code
• Add TSDoc/JSDoc to document the code