fix: cannot install without prefix (#4001)

framework/core/src/Database/Migrator.php

@@ -252,7 +252,7 @@ class Migrator
 
             $statement = str_replace(
                 'db_prefix_',
-                $this->connection->getTablePrefix(),
+                $this->connection->getTablePrefix() ?? '',
                 $statement
             );
             $this->connection->statement($statement);

framework/core/src/Install/DatabaseConfig.php

@@ -21,7 +21,7 @@ class DatabaseConfig implements Arrayable
         private string $database,
         private readonly ?string $username,
         private readonly ?string $password,
-        private readonly string $prefix
+        private readonly ?string $prefix
     ) {
         $this->validate();
     }