check nix develop shell in GitHub Action

Author: peterbecich

.github/workflows/nix-flake.yml

@@ -18,16 +18,20 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4
-    - uses: cachix/install-nix-action@v23
+    - uses: cachix/install-nix-action@v24
       with:
         extra_nix_config: |
           trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= hackage-server.cachix.org-1:iw0iRh6+gsFIrxROFaAt5gKNgIHejKjIfyRdbpPYevY=
           substituters = https://hydra.iohk.io https://cache.nixos.org/ https://hackage-server.cachix.org/
-    - uses: cachix/cachix-action@v12
+    - uses: cachix/cachix-action@v13
       with:
         # https://nix.dev/tutorials/continuous-integration-github-actions#setting-up-github-actions
         name: hackage-server
         authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+
+    - name: "Check `nix develop` shell"
+      run: nix develop --check
+
     - run: nix build
 
     - continue-on-error: false