`create-next-app` templates: Change `bun run dev` commands to `bun dev` (#55603)
[As of Bun v1.0.0](https://bun.sh/blog/bun-v1.0#changelog-since-v0-8), `bun dev` runs the "dev" script from package.json. Therefore, as with Yarn and pnpm, the "run" command is not necessary.
This PR changes the `create-next-app` README templates to show `bun dev` instead of `bun run dev`.