cli/command/trust: remove TestGetSignableRolesForTargetAndRemoveError

This test was only testing trust.GetSignableRoles to return an error
if it's offline, which was duplicating the [TestGetSignableRolesError]
test.

[TestGetSignableRolesError]: https://github.com/docker/cli/blob/fe0a8d27912dc6fddc60cedcd35bbef27b776355/cli/trust/trust_test.go#L49-L55

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/trust/revoke_test.go

@@ -9,8 +9,6 @@ import (
 	"github.com/docker/cli/internal/test"
 	"github.com/docker/cli/internal/test/notary"
 	"github.com/theupdateframework/notary/client"
-	"github.com/theupdateframework/notary/passphrase"
-	"github.com/theupdateframework/notary/trustpinning"
 	"gotest.tools/v3/assert"
 	is "gotest.tools/v3/assert/cmp"
 	"gotest.tools/v3/golden"
@@ -151,14 +149,6 @@ func TestTrustRevokeCommand(t *testing.T) {
 	}
 }
 
-func TestGetSignableRolesForTargetAndRemoveError(t *testing.T) {
-	notaryRepo, err := client.NewFileCachedRepository(t.TempDir(), "gun", "https://localhost", nil, passphrase.ConstantRetriever("password"), trustpinning.TrustPinConfig{})
-	assert.NilError(t, err)
-	target := client.Target{}
-	err = getSignableRolesForTargetAndRemove(target, notaryRepo)
-	assert.Error(t, err, "client is offline")
-}
-
 func TestRevokeTrustPromptTermination(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	t.Cleanup(cancel)