Support classification of indirect test dependencies.

[schmidtw]

To help understand what indirect dependencies, it would be ideal to support different require groups:

• direct, production
• indirect, production
• direct, test
• indirect, test

This will allow a mod file like this:

module github.com/example/example

go 1.25.3

require (
	github.com/coder/websocket v1.8.14
	github.com/foxcpp/go-mockdns v1.1.0
	github.com/go-git/go-billy/v6 v6.0.0-20251120215217-80673c4ccbfb
	github.com/golang-jwt/jwt/v5 v5.3.0
	github.com/google/uuid v1.6.0
	github.com/lmittmann/tint v1.1.2
	github.com/stretchr/testify v1.11.1
	github.com/tinylib/msgp v1.5.0
	github.com/xmidt-org/eventor v1.0.23
	github.com/xmidt-org/retry v0.0.4
	github.com/xmidt-org/wrp-go/v5 v5.4.0
	github.com/xmidt-org/wrpslog v0.1.0
)

require (
	github.com/davecgh/go-spew v1.1.1 // indirect
	github.com/google/go-cmp v0.7.0 // indirect
	github.com/miekg/dns v1.1.62 // indirect
	github.com/philhofer/fwd v1.2.0 // indirect
	github.com/pmezard/go-difflib v1.0.0 // indirect
	golang.org/x/mod v0.27.0 // indirect
	golang.org/x/net v0.43.0 // indirect
	golang.org/x/sync v0.16.0 // indirect
	golang.org/x/sys v0.38.0 // indirect
	golang.org/x/tools v0.36.0 // indirect
	gopkg.in/yaml.v3 v3.0.1 // indirect
)

To potentially be converted to this:

module github.com/example/example

go 1.25.3

require (
        github.com/coder/websocket v1.8.14
        github.com/go-git/go-billy/v6 v6.0.0-20251120215217-80673c4ccbfb
        github.com/golang-jwt/jwt/v5 v5.3.0
        github.com/google/uuid v1.6.0
        github.com/lmittmann/tint v1.1.2
        github.com/tinylib/msgp v1.5.0
        github.com/xmidt-org/eventor v1.0.23
        github.com/xmidt-org/retry v0.0.4
        github.com/xmidt-org/wrp-go/v5 v5.4.0
        github.com/xmidt-org/wrpslog v0.1.0
)

require github.com/philhofer/fwd v1.2.0 // indirect

require (
        github.com/foxcpp/go-mockdns v1.1.0 // test
        github.com/stretchr/testify v1.11.1 // test
)

require (
        github.com/davecgh/go-spew v1.1.1 // indirect; test
        github.com/miekg/dns v1.1.62 // indirect; test
        github.com/pmezard/go-difflib v1.0.0 // indirect; test
        golang.org/x/net v0.43.0 // indirect; test
        golang.org/x/sys v0.38.0 // indirect; test
        gopkg.in/yaml.v3 v3.0.1 // indirect; test
        github.com/google/go-cmp v0.7.0 // indirect; test
        golang.org/x/mod v0.27.0 // indirect; test
        golang.org/x/sync v0.16.0 // indirect; test
        golang.org/x/tools v0.36.0 // indirect; test
)