The ability to more easily see what are test-only dependencies for modules is a common request for cmd/go.
Consider supporting it here, either by highlighting a test-only dependency or by highlighting a non-test dependency.
There are different ways to determine this, but one way is this, which shows the modules used in your build excluding test-only dependencies:
go list -deps -f '{{with .Module}}{{.Path}} {{.Version}}{{end}}' ./... | sort -u