Update based on review

Author: ajcvickers

src/EFCore/Metadata/Conventions/ElementMappingConvention.cs

@@ -42,7 +42,7 @@ void Validate(IConventionTypeBase typeBase)
                 var typeMapping = Dependencies.TypeMappingSource.FindMapping((IProperty)property);
                 if (typeMapping is { ElementTypeMapping: not null })
                 {
-                    property.SetElementType(property.ClrType.TryGetElementType(typeof(IEnumerable<>)));
+                    property.Builder.SetElementType(property.ClrType.TryGetElementType(typeof(IEnumerable<>)));
                 }
             }
 

src/EFCore/Metadata/Conventions/ElementTypeChangedConvention.cs

@@ -39,7 +39,7 @@ public void ProcessPropertyElementTypeChanged(
             foreach (var foreignKey in key.GetReferencingForeignKeys())
             {
                 var foreignKeyProperty = foreignKey.Properties[index];
-                foreignKeyProperty.SetElementType(newElementType?.ClrType);
+                foreignKeyProperty.Builder.SetElementType(newElementType?.ClrType);
             }
         }
     }
@@ -52,7 +52,7 @@ public void ProcessForeignKeyAdded(
         var principalKeyProperties = foreignKeyBuilder.Metadata.PrincipalKey.Properties;
         for (var i = 0; i < foreignKeyProperties.Count; i++)
         {
-            foreignKeyProperties[i].SetElementType(principalKeyProperties[i].GetElementType()?.ClrType);
+            foreignKeyProperties[i].Builder.SetElementType(principalKeyProperties[i].GetElementType()?.ClrType);
         }
     }
 }