Removed obsolete method

[Zeegaan]

Fixes: #11081

Notes

• Removed obsolete migration method from UmbracoPocoDataBuilder

How to test

• Run a clean install
• When the tour popup shows, press "do not show again"
• Reload the page and verify that the popup doesn't show
• Create a migration class, I used this:

namespace Umbraco.Cms.Infrastructure.Migrations
{
    public class MyMigration : MigrationBase
    {
        public MyMigration(IMigrationContext context) : base(context)
        {
        }

        protected override void Migrate()
        {
            
        }
    }
}

• Create a fake migration in UmbracoPlan.cs with To<MyMigration>("47C4C7DF-4977-45F6-A6D4-8DC727BC8FE7");
• Run Umbraco and run the migration by pressing continue
• Verify that the tour popup doesn't show

[nikolajlauridsen]

LGTM, just need to wait for the build server to be happyy