Remove reference to ltsc2016 variants (EOL)

See https://docs.microsoft.com/en-us/virtualization/windowscontainers/deploy-containers/base-image-lifecycle and docker-library/official-images#11661

Author: tianon

apply-templates.sh

@@ -45,7 +45,7 @@ for version; do
 			windows/*)
 				variant="$(basename "$variant")" # "windowsservercore-1809", etc
 				windowsVariant="${variant%%-*}" # "windowsservercore", "nanoserver"
-				windowsRelease="${variant#$windowsVariant-}" # "1809", "ltsc2016", etc
+				windowsRelease="${variant#$windowsVariant-}" # "ltsc2022", "1809", etc
 				windowsVariant="${windowsVariant#windows}" # "servercore", "nanoserver"
 				export windowsVariant windowsRelease
 				template="Dockerfile-windows-$windowsVariant.template"