`go run` fails

[hajimehoshi]

% go version
go version go1.23.1 darwin/arm64

% go run github.com/go-gl/example/gl21-cube@latest
2024/11/04 05:07:23 Unable to find Go package in your GOPATH, it's needed to load assets: no required module provides package github.com/go-gl/example/gl21-cube: go.mod file not found in current directory or any parent directory; see 'go help modules'
exit status 1

Cloning this repository and running go run ./gl21-cube worked.