fix: ensure uniqueness (#6956)

* fix: ensure uniqueness

* only update wrong ones

* Update cmd/setup/16.go

Co-authored-by: Silvan <silvan.reusser@gmail.com>

---------

Co-authored-by: Silvan <silvan.reusser@gmail.com>

cmd/setup/16.go

@@ -0,0 +1,33 @@
+package setup
+
+import (
+	"context"
+	_ "embed"
+
+	"github.com/zitadel/logging"
+
+	"github.com/zitadel/zitadel/internal/database"
+)
+
+var (
+	//go:embed 16.sql
+	uniqueConstraintLower string
+)
+
+type UniqueConstraintToLower struct {
+	dbClient *database.DB
+}
+
+func (mig *UniqueConstraintToLower) Execute(ctx context.Context) error {
+	res, err := mig.dbClient.ExecContext(ctx, uniqueConstraintLower)
+	if err != nil {
+		return err
+	}
+	count, err := res.RowsAffected()
+	logging.WithFields("count", count).Info("unique constraints updated")
+	return err
+}
+
+func (mig *UniqueConstraintToLower) String() string {
+	return "16_unique_constraint_lower"
+}