rely on gitlab's built-in mirroring instead of CI

.gitlab-ci.yml

@@ -14,23 +14,6 @@ python3:
         - python3 setup.py build_ext -i
         - python3 test_tinyarray.py
 
-mirror:
-    only:
-        - branches@kwant/tinyarray
-    variables:
-      REPOS: "git@github.com:kwant-project/tinyarray.git git@gitlab.com:kwant/tinyarray.git"
-    before_script:
-      - HOSTS=$(for REPO in $REPOS; do echo ${REPO%:*} | cut -d'@' -f2; done)
-      - mkdir ~/.ssh && chmod 700 ~/.ssh
-      - for HOST in $HOSTS; do ssh-keyscan $HOST >> ~/.ssh/known_hosts; done
-      - echo "$DEPLOY_KEY" > ~/.ssh/id_rsa && chmod 600 ~/.ssh/id_rsa
-    after_script:
-      - rm -rf ~/.ssh
-    script:
-      - ORIGIN_URL=$(git config --get remote.origin.url)
-      - cd $(mktemp -d); git clone --bare $ORIGIN_URL .
-      - for REPO in $REPOS; do git push --mirror $REPO; done
-
 create conda dev package:
   image: condaforge/linux-anvil
   stage: deploy