Update cachix/install-nix-action action to v31 (#59)

Author: SuperSandroBot

.github/workflows/ci.yaml

@@ -38,7 +38,7 @@ jobs:
 
           sed -i'' "s/0\\.0\\.0-git/${{ steps.meta.outputs.version }}/" Cargo.lock
 
-      - uses: cachix/install-nix-action@v30
+      - uses: cachix/install-nix-action@v31
       - uses: DeterminateSystems/magic-nix-cache-action@v9
         with:
           diagnostic-endpoint: false