switch to cachix nix installer

The determinate one is deprecating the installation of the official nix.

.github/workflows/build.yaml

@@ -53,10 +53,13 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v5
       - name: Install Nix
-        uses: DeterminateSystems/nix-installer-action@main
+        uses: cachix/install-nix-action@v31
         with:
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          extra-conf: "system-features = nixos-test benchmark big-parallel kvm"
+          github_access_token: ${{ secrets.GITHUB_TOKEN }}
+          enable_kvm: true
+          extra_nix_config: |
+            keep-outputs = true
+            keep-failed = true
       - name: Setup Caching
         uses: cachix/cachix-action@v16
         with:
@@ -80,10 +83,13 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v5
       - name: Install Nix
-        uses: DeterminateSystems/nix-installer-action@main
+        uses: cachix/install-nix-action@v31
         with:
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          extra-conf: "system-features = nixos-test benchmark big-parallel kvm"
+          github_access_token: ${{ secrets.GITHUB_TOKEN }}
+          enable_kvm: true
+          extra_nix_config: |
+            keep-outputs = true
+            keep-failed = true
       - name: Setup Caching
         uses: cachix/cachix-action@v16
         with:
@@ -108,10 +114,13 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v5
       - name: Install Nix
-        uses: DeterminateSystems/nix-installer-action@main
+        uses: cachix/install-nix-action@v31
         with:
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          extra-conf: "system-features = nixos-test benchmark big-parallel kvm"
+          github_access_token: ${{ secrets.GITHUB_TOKEN }}
+          enable_kvm: true
+          extra_nix_config: |
+            keep-outputs = true
+            keep-failed = true
       - name: Setup Caching
         uses: cachix/cachix-action@v16
         with:

.github/workflows/demo.yml

@@ -60,8 +60,14 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v5
 
-      - name: Install nix
+      - name: Install Nix
         uses: cachix/install-nix-action@v31
+        with:
+          github_access_token: ${{ secrets.GITHUB_TOKEN }}
+          enable_kvm: true
+          extra_nix_config: |
+            keep-outputs = true
+            keep-failed = true
 
       - uses: cachix/cachix-action@v16
         with:

.github/workflows/lock-update.yaml

@@ -12,10 +12,9 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v5
       - name: Install Nix
-        uses: DeterminateSystems/nix-installer-action@main
+        uses: cachix/install-nix-action@v31
         with:
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          extra-conf: "system-features = nixos-test benchmark big-parallel kvm"
+          github_access_token: ${{ secrets.GITHUB_TOKEN }}
       - name: Update flake.lock
         uses: DeterminateSystems/update-flake-lock@main
         with:

.github/workflows/pages.yml

@@ -31,8 +31,10 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v5
 
-      - name: Install nix
+      - name: Install Nix
         uses: cachix/install-nix-action@v31
+        with:
+          github_access_token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Setup Caching
         uses: cachix/cachix-action@v16