fix(admin): update password hashing method-Replace custom password function with PHP's built-in password_hash

- Improve password security in admin controller

app/admin/controller/system/Admin.php

@@ -114,7 +114,7 @@ class Admin extends AdminController
             }
             try {
                 $save = $row->save([
-                    'password' => password($post['password']),
+                    'password' => password_hash($post['password'], PASSWORD_DEFAULT),
                 ]);
             }catch (\Exception $e) {
                 $this->error('保存失败');