tutorials: need "go mod tidy"

**Describe the bug**
[`tutorials/go.mod`](./blob/main/tutorials/go.mod) needs an update of dependencies.

**To Reproduce**
```console
$ go version
go version go1.24.1 darwin/arm64
$ git clone https://github.com/charmbracelet/bubbletea.git
$ cd bubbletea
$ cd tutorials/commands
$ go run .
go: updates to go.mod needed; to update it:
go mod tidy
```

Start with tutorials/go.mod and reproduce the issue from tutorials/commands using the reported Go version and go run .. Run go mod tidy in the tutorials module, review the dependency changes, and verify that the command runs without requesting a go.mod update.

Written by the indexing model from the issue text.