Drop Ubuntu 16.04 from gitlab-ci, add 20.04 instead

.gitlab-ci.yml

@@ -17,7 +17,7 @@ variables:
   stage: build
   before_script:
    - apt-get update
-   - apt-get -y install build-essential git cmake libpng-dev libjpeg-dev libxxf86vm-dev libgl1-mesa-dev libsqlite3-dev libleveldb-dev libogg-dev libvorbis-dev libopenal-dev libcurl4-gnutls-dev libfreetype6-dev zlib1g-dev libgmp-dev libjsoncpp-dev libzstd-dev
+   - DEBIAN_FRONTEND=noninteractive apt-get -y install build-essential git cmake libpng-dev libjpeg-dev libxxf86vm-dev libgl1-mesa-dev libsqlite3-dev libleveldb-dev libogg-dev libvorbis-dev libopenal-dev libcurl4-gnutls-dev libfreetype6-dev zlib1g-dev libgmp-dev libjsoncpp-dev libzstd-dev
   script:
     - git clone https://github.com/minetest/irrlicht -b $IRRLICHT_TAG lib/irrlichtmt
     - mkdir cmakebuild
@@ -134,49 +134,49 @@ deploy:debian-11:
 ## Ubuntu
 ##
 
-# Xenial
+# Bionic
 
-build:ubuntu-16.04:
+build:ubuntu-18.04:
   extends: .build_template
-  image: ubuntu:xenial
+  image: ubuntu:bionic
 
-package:ubuntu-16.04:
+package:ubuntu-18.04:
   extends: .debpkg_template
-  image: ubuntu:xenial
+  image: ubuntu:bionic
   needs:
-    - build:ubuntu-16.04
+    - build:ubuntu-18.04
   variables:
     JSONCPP_PKG: libjsoncpp1
     LEVELDB_PKG: libleveldb1v5
     JPEG_PKG: libjpeg-turbo8
 
-deploy:ubuntu-16.04:
+deploy:ubuntu-18.04:
   extends: .debpkg_install
-  image: ubuntu:xenial
+  image: ubuntu:bionic
   needs:
-    - package:ubuntu-16.04
+    - package:ubuntu-18.04
 
-# Bionic
+# Focal
 
-build:ubuntu-18.04:
+build:ubuntu-20.04:
   extends: .build_template
-  image: ubuntu:bionic
+  image: ubuntu:focal
 
-package:ubuntu-18.04:
+package:ubuntu-20.04:
   extends: .debpkg_template
-  image: ubuntu:bionic
+  image: ubuntu:focal
   needs:
-    - build:ubuntu-18.04
+    - build:ubuntu-20.04
   variables:
     JSONCPP_PKG: libjsoncpp1
-    LEVELDB_PKG: libleveldb1v5
+    LEVELDB_PKG: libleveldb1d
     JPEG_PKG: libjpeg-turbo8
 
-deploy:ubuntu-18.04:
+deploy:ubuntu-20.04:
   extends: .debpkg_install
-  image: ubuntu:bionic
+  image: ubuntu:focal
   needs:
-    - package:ubuntu-18.04
+    - package:ubuntu-20.04
 
 ##
 ## Fedora