chore: drop Windows Server 2012 R2

EOL since October 10, 2023.

README.md

@@ -40,7 +40,7 @@ required to run the virtual machines.
 - Host support for **Linux and macOS**
 - **macOS** Sonoma, Ventura, Monterey, Big Sur, Catalina & Mojave
 - **Windows** 10 and 11 including TPM 2.0
-- **Windows Server** 2022 2019 2016 2012-r2
+- **Windows Server** 2022 2019 2016
 - [Ubuntu](https://ubuntu.com/desktop) and all the **[official Ubuntu
   flavours](https://ubuntu.com/download/flavours)**
 - **Nearly 1000 operating system editions are supported!**

quickget

@@ -1179,7 +1179,7 @@ function languages_windows() {
 }
 
 function releases_windows-server() {
-    echo 2022 2019 2016 2012-r2
+    echo 2022 2019 2016
 }
 
 function languages_windows-server() {
@@ -3046,7 +3046,6 @@ function download_windows_server() {
 
     case "${RELEASE}" in
         "10-ltsc") PRETTY_RELEASE="10 LTSC";;
-        "2012-r2") PRETTY_RELEASE="2012 R2";;
         *) PRETTY_RELEASE="${RELEASE}";;
     esac