Frequently clean runner nix store

.gitlab-ci.yml

@@ -8,6 +8,7 @@ variables:
 stages:
   - test
   - deploy
+  - scheduled
 
 before_script:
   - mv .gitlab/passwd /etc/passwd
@@ -44,7 +45,7 @@ deploy:
 
 
 check updates:
-  stage: test
+  stage: scheduled
   script:
     # Prepare git access
     - nix-env -iA nixos.openssh
@@ -65,3 +66,9 @@ check updates:
   rules:
     - if: $CI_PIPELINE_SOURCE == "schedule"
 
+clean nix store:
+  stage: scheduled
+  script:
+    - nix-collect-garbage --delete-older-than 14d
+  rules:
+    - if: $CI_PIPELINE_SOURCE == "schedule"