title: GORM minSize constraint is ignored
body: <p>In my Grails 3.3.5 app, I have the following domain classes</p>
  
  <pre><code>class Evidence {
  
      String customer
      static hasMany = [images: Image]
  
      static constraints = {
          images minSize: 1
      }
  }
  
  class Image {
      String url
      static belongsTo = [evidence: Evidence]
  }
  </code></pre>
  
  <p>It seems the <code>minSize</code> constraint is being ignored, because if I execute</p>
  
  <pre><code>new Evidence(customer: 'test').save(failOnError: true)
  </code></pre>
  
  <p>the object is saved in the <code>evidence</code> table even though there are no images mapped to it.</p>