Fix incorrect duplicated property notification call

Author: Sergio0694

CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservablePropertyGenerator.Execute.cs

@@ -200,8 +200,6 @@ bool IsPropertyNameValidWithGeneratedMembers(string propertyName)
                         otherFieldSymbol.HasAttributeWithFullyQualifiedName("global::CommunityToolkit.Mvvm.ComponentModel.ObservablePropertyAttribute") &&
                         propertyName == GetGeneratedPropertyName(otherFieldSymbol))
                     {
-                        propertyChangedNames.Add(propertyName);
-
                         return true;
                     }
                 }