Adjust default workspace naming prompt

The previous version is a little overdramatic and somewhat accusatory.
Just lay it out how it is: TFC needs workspaces to be named.

internal/cloud/e2e/migrate_state_multi_to_tfc_test.go

@@ -307,7 +307,7 @@ func Test_migrate_multi_to_tfc_cloud_tags_strategy(t *testing.T) {
 					commands: []tfCommand{
 						{
 							command:           []string{"init", "-migrate-state"},
-							expectedCmdOutput: `Terraform Cloud configuration only allows named workspaces!`,
+							expectedCmdOutput: `Terraform Cloud requires all workspaces to be given an explicit name.`,
 							userInput:         []string{"dev", "1", "app-*", "1"},
 							postInputOutput: []string{
 								`Would you like to rename your workspaces?`,

internal/cloud/e2e/migrate_state_remote_backend_to_tfc_test.go

@@ -379,7 +379,7 @@ func Test_migrate_remote_backend_name_to_tfc_tags(t *testing.T) {
 					commands: []tfCommand{
 						{
 							command:           []string{"init", "-migrate-state", "-ignore-remote-version"},
-							expectedCmdOutput: `Terraform Cloud configuration only allows named workspaces!`,
+							expectedCmdOutput: `Terraform Cloud requires all workspaces to be given an explicit name.`,
 							userInput:         []string{"cloud-workspace", "yes"},
 							postInputOutput: []string{
 								`Do you want to copy existing state to Terraform Cloud?`,
@@ -741,7 +741,7 @@ func Test_migrate_remote_backend_prefix_to_tfc_tags(t *testing.T) {
 					commands: []tfCommand{
 						{
 							command:           []string{"init", "-migrate-state", "-ignore-remote-version"},
-							expectedCmdOutput: `The Terraform Cloud configuration only allows named workspaces!`,
+							expectedCmdOutput: `Terraform Cloud requires all workspaces to be given an explicit name.`,
 							userInput:         []string{"cloud-workspace", "yes"},
 							postInputOutput: []string{
 								`Do you want to copy existing state to Terraform Cloud?`,

internal/cloud/e2e/migrate_state_single_to_tfc_test.go

@@ -103,7 +103,7 @@ func Test_migrate_single_to_tfc(t *testing.T) {
 					commands: []tfCommand{
 						{
 							command:           []string{"init", "-migrate-state"},
-							expectedCmdOutput: `Terraform Cloud configuration only allows named workspaces!`,
+							expectedCmdOutput: `Terraform Cloud requires all workspaces to be given an explicit name.`,
 							userInput:         []string{"new-workspace", "yes"},
 							postInputOutput: []string{
 								`Do you want to copy existing state to Terraform Cloud?`,

internal/cloud/e2e/migrate_state_tfc_to_tfc_test.go

@@ -134,7 +134,7 @@ func Test_migrate_tfc_to_tfc_single_workspace(t *testing.T) {
 					commands: []tfCommand{
 						{
 							command:           []string{"init", "-migrate-state", "-ignore-remote-version"},
-							expectedCmdOutput: `The Terraform Cloud configuration only allows named workspaces!`,
+							expectedCmdOutput: `Terraform Cloud requires all workspaces to be given an explicit name.`,
 							userInput:         []string{"new-workspace", "yes"},
 							postInputOutput: []string{
 								`Do you want to copy existing state to Terraform Cloud?`,
@@ -205,7 +205,7 @@ func Test_migrate_tfc_to_tfc_single_workspace(t *testing.T) {
 					commands: []tfCommand{
 						{
 							command:           []string{"init", "-migrate-state"},
-							expectedCmdOutput: `The Terraform Cloud configuration only allows named workspaces!`,
+							expectedCmdOutput: `Terraform Cloud requires all workspaces to be given an explicit name.`,
 							expectError:       true,
 							userInput:         []string{"new-workspace", "yes"},
 						},

internal/command/meta_backend_migrate.go

@@ -694,8 +694,7 @@ func (m *Meta) promptNewWorkspaceName(destinationType string) (string, error) {
 	message := fmt.Sprintf("[reset][bold][yellow]The %q backend configuration only allows "+
 		"named workspaces![reset]", destinationType)
 	if destinationType == "cloud" {
-		message = fmt.Sprintf("[reset][bold][yellow]The Terraform Cloud configuration only allows " +
+		message = `[reset][bold][yellow]Terraform Cloud requires all workspaces to be given an explicit name.[reset]`
-			"named workspaces![reset]")
 	}
 	name, err := m.UIInput().Input(context.Background(), &terraform.InputOpts{
 		Id:          "new-state-name",
@@ -896,7 +895,7 @@ If you answer "yes", Terraform will migrate all states. If you answer
 
 const inputBackendNewWorkspaceName = `
 Please provide a new workspace name (e.g. dev, test) that will be used
-to migrate the existing default workspace. 
+to migrate the existing default workspace.
 `
 
 const inputBackendSelectWorkspace = `