Ignore nix job steps (#1672)

Co-authored-by: Potato Hatsue <[email protected]>

Author: jneira

.github/workflows/nix.yml

@@ -19,7 +19,6 @@ jobs:
 
   nix:
     needs: pre_job
-    if: ${{ needs.pre_job.outputs.should_skip != 'true' }}
     runs-on: ${{ matrix.os }}
 
     strategy:
@@ -29,14 +28,18 @@ jobs:
         os: [ubuntu-latest, macOS-latest]
 
     steps:
-    - uses: actions/checkout@v2
+    - if: ${{ needs.pre_job.outputs.should_skip != 'true' }}
+      uses: actions/checkout@v2
       with:
         submodules: true
-    - uses: cachix/install-nix-action@v12
+    - if: ${{ needs.pre_job.outputs.should_skip != 'true' }}
+      uses: cachix/install-nix-action@v12
       with:
         nix_path: nixpkgs=channel:nixos-unstable
-    - uses: cachix/cachix-action@v8
+    - if: ${{ needs.pre_job.outputs.should_skip != 'true' }}
+      uses: cachix/cachix-action@v8
       with:
         name: haskell-language-server
         authToken: ${{ secrets.HLS_CACHIX_AUTH_TOKEN }}
-    - run: nix-shell --argstr compiler ${{ matrix.ghc }} --run "cabal update && cabal build"
+    - if: ${{ needs.pre_job.outputs.should_skip != 'true' }}
+      run: nix-shell --argstr compiler ${{ matrix.ghc }} --run "cabal update && cabal build"