Remove the CI workflow, we use garnix.io instead.

.github/workflows/ci.yml

@@ -1,27 +0,0 @@
-name: CI
-
-on:
-  push:
-    branches: [ "main" ]
-  pull_request:
-    branches: [ "main" ]
-
-env:
-  CARGO_TERM_COLOR: always
-
-jobs:
-  build:
-
-    runs-on: "nix"
-
-    steps:
-    - uses: "actions/checkout@v3"
-    - uses: "cachix/install-nix-action@master"
-      with:
-        github_access_token: "${{ secrets.GITHUB_TOKEN }}"
-    - name: "Build"
-      run: |
-        nix build '.#system-manager'
-    - name: "Run tests"
-      run: |
-        nix flake check