Apt error upgrading tonight

sudo  apt update ; sudo apt upgrade ;
... (nothing out of the ordinary looking) ....
42 packages can be upgraded. Run 'apt list --upgradable' to see them.
Notice: Missing Signed-By in the sources.list(5) entry for 'https://mntre.com/reform-debian-repo'
Notice: Some sources can be modernized. Run 'apt modernize-sources' to do so.
Upgrading:                      
  evince  evince-common  gstreamer1.0-plugins-good  gstreamer1.0-pulseaudio  libevdocument3-4t64  libevview3-3t64

Not upgrading:
  libkf6colorscheme6    libkf6iconwidgets6    libqt6dbus6          libqt6qml6               libqt6quickwidgets6   libqt6waylandcompositor6   minetest-data          qt6ct
  libkf6configwidgets6  libkf6windowsystem6   libqt6gui6           libqt6qmlmodels6         libqt6sql6            libqt6widgets6             qt6-gtk-platformtheme
  libkf6globalaccel6    libkirigamiplatform6  libqt6network6       libqt6quick6             libqt6sql6-sqlite     libqt6wlshellintegration6  qt6-qpa-plugins
  libkf6iconthemes-bin  libqt6concurrent6     libqt6opengl6        libqt6quickcontrols2-6   libqt6svg6            libqt6xml6                 qt6-svg-plugins
  libkf6iconthemes6     libqt6core6t64        libqt6printsupport6  libqt6quicktemplates2-6  libqt6waylandclient6  minetest                   qt6-wayland

Summary:
  Upgrading: 6, Installing: 0, Removing: 0, Not Upgrading: 36
  Download size: 4,231 kB
  Space needed: 524 kB / 1,831 GB available

Let me know if I can clarify anything.