Show the user who rents the most books with php laravel

I want to show the user who rents the most books with php laravel, but I get an error like this, what is the reason for the error? error: Undefined property: stdClass::$user

This is my code:

$kiras = DB::table('kiras')
        ->select('user_id',DB::raw('count(*) as total'))
        ->groupBy('user_id')
        ->orderBy('total','DESC')
        ->take(1)
        ->get();

        return view('livewire.home-component',[
            'kiras'=>$kiras,
            ])->layout('layouts.base');

Page:

<div class="panel-body">
              <div class="col-md-10">
                    <div class="card" style="width: 20rem;">
                         <div class="card-body">
                          <h4 class="card-title">User who rents the most books : </h4>
                                @foreach($kiras as $kira)
                                       {{$kira->user->name}}
                                @endforeach
                         </div>
             </div>
      </div>
 </div>

Rent table:

Schema::create('kiras', function (Blueprint $table) {
            $table->id();
            $table->bigInteger('user_id')->unsigned()->nullable();
            $table->bigInteger('kitap_id')->unsigned()->nullable();
            $table->date('AlimTarihi')->nullable();
            $table->date('TeslimTarihi')->nullable();
            $table->enum('durum',['Edildi','Edilmedi'])->default('Edilmedi');
            $table->timestamps();
            $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
            $table->foreign('kitap_id')->references('id')->on('kitaplars')->onDelete('cascade');
        });

User table :

Schema::create('users', function (Blueprint $table) {
            $table->id();
            $table->string('name');
            $table->string('lastName')->nullable();
            $table->BigInteger('Yasi')->nullable();
            $table->string('Adres')->nullable();
            $table->string('email')->unique();
            $table->timestamp('email_verified_at')->nullable();
            $table->string('password');
            $table->rememberToken();
            $table->foreignId('current_team_id')->nullable();
            $table->string('profile_photo_path', 2048)->nullable();
            $table->string('utype')->default('USR')->comment('Yonetici icin ADM Kullanici icin USR');
            $table->timestamps();
        });

Rental table model :

public function user()
    {
        return $this->belongsTo(User::class,'user_id');
    }