CI: Update install-nix-action to v23

Author: joachimschmidt557

.github/workflows/build.yml

@@ -10,12 +10,9 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v3
-    - uses: cachix/install-nix-action@v19
+    - uses: cachix/install-nix-action@v23
       with:
-        install_url: https://nixos-nix-install-tests.cachix.org/serve/vij683ly7sl95nnhb67bdjjfabclr85m/install
-        install_options: '--tarball-url-prefix https://nixos-nix-install-tests.cachix.org/serve'
-        extra_nix_config: |
-          experimental-features = nix-command flakes
+        github_access_token: ${{ secrets.GITHUB_TOKEN }}
     - uses: cachix/cachix-action@v12
       with:
         name: nimmm