ci/check: remove (it is now empty)

.github/workflows/check.yml

@@ -1,21 +0,0 @@
-name: Run checks on code
-
-on:
-  pull_request:
-  push:
-
-jobs:
-  check:
-    name: Check that the module is valid
-    runs-on: ubuntu-latest
-    timeout-minutes: 40
-    steps:
-      - uses: actions/checkout@v4
-      - uses: cachix/install-nix-action@v20
-        with:
-          nix_path: nixpkgs=channel:nixos-unstable
-          github_access_token: ${{ secrets.GITHUB_TOKEN }}
-      - uses: cachix/cachix-action@v13
-        with:
-          name: nix-community
-          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'