build: remove .gitlab-ci.yml

.gitlab-ci.yml

@@ -1,28 +0,0 @@
-image: nixos/nix:2.9.1
-
-variables:
-  NIX_CONFIG: "experimental-features = nix-command flakes"
-
-before_script:
-  - nix-env -iA cachix -f https://cachix.org/api/v1/install
-  - cachix use felschr
-
-stages:
-  - test
-  - build
-
-check:
-  stage: test
-  script:
-    - cachix watch-exec felschr nix flake check --no-build
-
-build:
-  stage: build
-  script:
-    - cachix watch-exec felschr nix build .#deconz
-    - cachix watch-exec felschr nix build .#nixosConfigurations.home-server.config.system.build.toplevel
-    # disabled because GitLab.com runner runs out of space
-    # - cachix watch-exec felschr nix build .#nixosConfigurations.home-pc.config.system.build.toplevel
-  only:
-    - main
-  allow_failure: true