fix: added typescript dependency in next-sitemap example (#25866)
fix: added typescript dependency in next-sitemap example (#25866)

As mentioned in #25854 `witn-next-sitemap` example is missing `typescript` package as a dependency

- [x] Make sure the linting passes

flybayer/next.js,JeromeFitz/next.js,azukaru/next.js,JeromeFitz/next.js,zeit/next.js,zeit/next.js,azukaru/next.js,zeit/next.js,flybayer/next.js,JeromeFitz/next.js,flybayer/next.js,azukaru/next.js,azukaru/next.js,flybayer/next.js,JeromeFitz/next.js