Remove 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

1.6/windows/windowsservercore-ltsc2016/Dockerfile

@@ -44,7 +44,7 @@ for version; do
 		case "$dir" in
 			windows/*)
 				windowsVariant="${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"

1.7/windows/windowsservercore-ltsc2016/Dockerfile

@@ -44,8 +44,7 @@
       "alpine3.15",
       "alpine3.14",
       "windows/windowsservercore-ltsc2022",
-      "windows/windowsservercore-1809",
-      "windows/windowsservercore-ltsc2016"
+      "windows/windowsservercore-1809"
     ],
     "version": "1.6.5"
   },
@@ -94,8 +93,7 @@
       "alpine3.15",
       "alpine3.14",
       "windows/windowsservercore-ltsc2022",
-      "windows/windowsservercore-1809",
-      "windows/windowsservercore-ltsc2016"
+      "windows/windowsservercore-1809"
     ],
     "version": "1.7.1"
   }

apply-templates.sh

@@ -97,8 +97,7 @@ for version in "${versions[@]}"; do
 			else empty end,
 			if .arches | has("windows-amd64") then
 				"ltsc2022",
-				"1809",
-				"ltsc2016"
+				"1809"
 				| "windows/windowsservercore-" + .
 			else empty end
 		])