diff --git a/.github/workflows/build-contributor-container-PR.yml b/.github/workflows/build-contributor-container-PR.yml
index e55ad88e..fc1d11b7 100644
--- a/.github/workflows/build-contributor-container-PR.yml
+++ b/.github/workflows/build-contributor-container-PR.yml
@@ -1,5 +1,6 @@
 name: 'Build Contributor container (PR)'
 # For speedup to do this in parallel: https://docs.docker.com/build/ci/github-actions/multi-platform/
+# Loosely based on: https://docs.docker.com/build/ci/github-actions/push-multi-registries/
 
 on:
   push:
diff --git a/.tarball-release.yml b/.tarball-release.yml
deleted file mode 100644
index 705627e9..00000000
--- a/.tarball-release.yml
+++ /dev/null
@@ -1,29 +0,0 @@
-# The jobs to do a manual DOMjudge release
-createtar:
-  stage: test
-  when: manual
-  image: domjudge/gitlabci:2.1
-  script:
-    - echo -e "\e[0Ksection_start:`date +%s`:buildrelease\r\e[0KBuild of release tarball"
-    - wget https://raw.githubusercontent.com/DOMjudge/domjudge-scripts/main/make_release.sh
-    - sh ./make_release.sh $DOMJUDGE_VERSION
-    - echo -e "\e[0Ksection_end:`date +%s`:buildrelease\r\e[0K"
-    - echo -e "\e[0Ksection_start:`date +%s`:aptpackages\r\e[0KInstall the expected packages for new release"
-    - apt update
-    - apt install -y acl zip unzip mariadb-server apache2 php php-fpm php-gd php-cli php-intl php-mbstring php-mysql php-curl php-json php-xml php-zip composer ntp
-    - apt install -y make pkg-config sudo debootstrap libcgroup-dev php-cli php-curl php-json php-xml php-zip lsof procps
-    - echo -e "\e[0Ksection_end:`date +%s`:aptpackages\r\e[0K"
-    - echo -e "\e[0Ksection_start:`date +%s`:testtar\r\e[0KTest the release tarball"
-    - tar zxvf domjudge-${DOMJUDGE_VERSION}.tar.gz
-    - cd domjudge-${DOMJUDGE_VERSION}
-    - ./configure
-    - make build
-    - make clean
-    - make all
-    - make clean
-    - make docs
-    - make clean
-    - make submitclient
-    - echo -e "\e[0Ksection_end:`date +%s`:testtar\r\e[0K"
-    - echo "See the new_release_howto.txt (L28/domjudge-scripts) for the next step."
-