imx8mn-ddr4-evk is listed as a supported target but is not in installer

imx8mn-ddr4-evk is listed as a supported target in the list of supported platforms, but it cannot be installed from production via installer UI.

Either remove imx8mn-ddr4-evk from https://doc.qt.io/Boot2Qt-6.2/qtdc-supported-platforms.html (if it's not supported) or add the package to the installer (which then is a task for Samuli or Mikko).