title: Remove add another from django admin
body: <p>I have an inline model in Django admin which is having <code>OneToOneField</code> relation with the parent.</p>
  
  <pre><code>class Child(models.Model):
   parent = models.OneToOneField(Parent)
   received_on = models.DateField(null=True,)
  </code></pre>
  
  <p>In admin Inline I don't want to show "add another button" so I have done something like this:-</p>
  
  <pre><code>class CampaignInfluencerShippingTrackingInline(admin.TabularInline):
      model = Child
      can_delete = False
      extra = 0
      fields = ['received_on']
  
      def has_add_permission(self, request):
           return False
  </code></pre>
  
  <p>But it is still showing add another button the problem is with relation with the parent as it is having <code>OneToOneField</code> if I try with <code>ForeignKey</code> with same code add another button is not showing but with <code>OneToOneField</code> it is always showing.</p>
  
  <p>Can anyone suggest me how it is working and what I can do to remove add another button from the Inline child?</p>
  
  <p>I am able to add the model inline in parent but my question is related how to remove "add another button" from inline model.</p>