actions: bump nix version

Author: doyougnu

.github/workflows/deploy.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
-    - uses: cachix/install-nix-action@v22
+    - uses: cachix/install-nix-action@v31
     - run:  nix build -o _build --no-sandbox
     - name: Deploy 🚀
       uses: JamesIves/github-pages-deploy-action@v4.2.2