[CI] cache /nix/store with collect garbage

.gitlab-ci.yml

@@ -35,25 +35,15 @@ compile:
   stage: compile
   cache:
     paths:
-      # - /tmp/nix-cache
-      #- /nix/store
+      - /nix/store
       #- node_modules/
       - output/
       #- .spago/
       #- ${CI_PROJECT_DIR}/bun.lockb
-  # before_script:
-  #   # restore old cache
-  #   - nix --extra-experimental-features "nix-command flakes" copy --from 'file:///tmp/nix-cache' || exit_code=$?
     
   script:
     - nix --extra-experimental-features "nix-command flakes" run .#fix-bun
-    #- nix-shell shell.nix --run fix-bun
     - nix --extra-experimental-features "nix-command flakes" run .#compile
-    #- nix-shell shell.nix --run compile
-
-  # after_script:
-  #   # store cache
-  #   - nix --extra-experimental-features "nix-command flakes" copy --to 'file:///tmp/nix-cache' .#build
 
 test:
   stage: test
@@ -61,18 +51,14 @@ test:
     # cache per branch name
     # key: ${CI_COMMIT_REF_SLUG}
     paths:
-      # - /tmp/nix-cache
-      #- /nix/store
+      - /nix/store
       #- node_modules/
       - output/
       #- .spago/
       #- ${CI_PROJECT_DIR}/bun.lockb
-  # before_script:
-  #   # restore old cache
-  #   - nix --extra-experimental-features "nix-command flakes" copy --from 'file:///tmp/nix-cache' || exit_code=$?
     
   script:
     - nix --extra-experimental-features "nix-command flakes" run .#fix-bun
-    #- nix-shell shell.nix --run fix-bun
     - nix --extra-experimental-features "nix-command flakes" run .#test-ps
-    #- nix-shell shell.nix --run test-ps
+    
+    - nix-collect-garbage