ci: update Nix to match versions in nixpkgs

.github/workflows/test.yml

@@ -12,13 +12,10 @@ jobs:
     timeout-minutes: 30
     steps:
     - uses: actions/checkout@v3
-    # We use the Determinate Systems installer for 2.18 because the
-    # Sequoia UID/GID changes have not yet been backported to the
-    # official installer for that version.
     - name: Install nix corresponding to latest stable channel
-      uses: DeterminateSystems/nix-installer-action@main
+      uses: cachix/install-nix-action@v30
       with:
-        nix-package-url: https://releases.nixos.org/nix/nix-2.18.5/nix-2.18.5-x86_64-darwin.tar.xz
+        install_url: https://releases.nixos.org/nix/nix-2.18.8/install
     - run: nix-build ./release.nix -I nixpkgs=channel:${{ env.CURRENT_STABLE_CHANNEL }} -I darwin=. -A tests
     - run: nix-build ./release.nix -I nixpkgs=channel:${{ env.CURRENT_STABLE_CHANNEL }} -I darwin=. -A manpages
     - run: nix-build ./release.nix -I nixpkgs=channel:${{ env.CURRENT_STABLE_CHANNEL }} -I darwin=. -A examples.simple
@@ -29,9 +26,9 @@ jobs:
     steps:
     - uses: actions/checkout@v3
     - name: Install nix from current unstable channel
-      uses: cachix/install-nix-action@v27
+      uses: cachix/install-nix-action@v30
       with:
-        install_url: https://releases.nixos.org/nix/nix-2.24.6/install
+        install_url: https://releases.nixos.org/nix/nix-2.24.9/install
     - run: nix-build ./release.nix -I nixpkgs=channel:nixpkgs-unstable -I darwin=. -A tests
     - run: nix-build ./release.nix -I nixpkgs=channel:nixpkgs-unstable -I darwin=. -A manpages
     - run: nix-build ./release.nix -I nixpkgs=channel:nixpkgs-unstable -I darwin=. -A examples.simple
@@ -41,20 +38,18 @@ jobs:
     timeout-minutes: 30
     steps:
     - uses: actions/checkout@v3
-    # We use the Determinate Systems installer for 2.18 because the
-    # Sequoia UID/GID changes have not yet been backported to the
-    # official installer for that version.
     - name: Install nix corresponding to latest stable channel
-      uses: DeterminateSystems/nix-installer-action@main
+      uses: cachix/install-nix-action@v30
       with:
-        nix-package-url: https://releases.nixos.org/nix/nix-2.18.5/nix-2.18.5-x86_64-darwin.tar.xz
+        install_url: https://releases.nixos.org/nix/nix-2.18.8/install
+        nix_path: nixpkgs=channel:${{ env.CURRENT_STABLE_CHANNEL }}
     - name: Install ${{ env.CURRENT_STABLE_CHANNEL }} channel
       run: |
         nix-channel --add https://nixos.org/channels/${{ env.CURRENT_STABLE_CHANNEL }} nixpkgs
         nix-channel --update
     - name: Install nix-darwin and test
       run: |
-        export NIX_PATH=nixpkgs=channel:${{ env.CURRENT_STABLE_CHANNEL }}
+        export NIX_PATH=$HOME/.nix-defexpr/channels
 
         # We run nix-darwin twice to test that it can create darwin-configuration correctly for us
         # but we expect it to fail setting up /etc/nix/nix.conf
@@ -89,9 +84,9 @@ jobs:
     steps:
     - uses: actions/checkout@v3
     - name: Install nix from current unstable channel
-      uses: cachix/install-nix-action@v27
+      uses: cachix/install-nix-action@v30
       with:
-        install_url: https://releases.nixos.org/nix/nix-2.24.6/install
+        install_url: https://releases.nixos.org/nix/nix-2.24.9/install
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Install nixpkgs-unstable channel
       run: |
@@ -133,13 +128,10 @@ jobs:
     timeout-minutes: 30
     steps:
     - uses: actions/checkout@v3
-    # We use the Determinate Systems installer for 2.18 because the
-    # Sequoia UID/GID changes have not yet been backported to the
-    # official installer for that version.
-    - name: Install nix corresponding to latest stable channel
-      uses: DeterminateSystems/nix-installer-action@main
+    - name: Install nix version corresponding to latest stable channel
+      uses: cachix/install-nix-action@v30
       with:
-        nix-package-url: https://releases.nixos.org/nix/nix-2.18.5/nix-2.18.5-x86_64-darwin.tar.xz
+        install_url: https://releases.nixos.org/nix/nix-2.18.8/install
     - name: Install nix-darwin
       run: |
         mkdir -p ~/.config/nix-darwin
@@ -220,9 +212,9 @@ jobs:
     steps:
     - uses: actions/checkout@v3
     - name: Install nix from current unstable channel
-      uses: cachix/install-nix-action@v27
+      uses: cachix/install-nix-action@v30
       with:
-        install_url: https://releases.nixos.org/nix/nix-2.24.6/install
+        install_url: https://releases.nixos.org/nix/nix-2.24.9/install
     - name: Install nix-darwin
       run: |
         mkdir -p ~/.config/nix-darwin

.github/workflows/update-manual.yml

@@ -17,7 +17,7 @@ jobs:
         fetch-depth: 0
 
     - name: Install Nix
-      uses: cachix/install-nix-action@v27
+      uses: cachix/install-nix-action@v30
 
     - name: Build manual
       run: |