ci: Update action versions

This might fix the CI since previously it would run out of disk space.

See: cachix/install-nix-action#199

.github/workflows/ci.yml

@@ -11,22 +11,22 @@ jobs:
     name: nix flake check
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
-    - uses: cachix/install-nix-action@v22
+    - uses: actions/checkout@v4
+    - uses: cachix/install-nix-action@v26
     - run: nix flake check
   format:
     name: nix fmt -- --check **/*.nix
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - uses: cachix/install-nix-action@v22
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v26
       - run: nix fmt -- --check **/*.nix
   example:
     name: nix flake check ./example
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - uses: cachix/install-nix-action@v22
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v26
       - run: cp ./hardware/laptop.nix ./example/hardware-configuration.nix
       - run: git add .
       - run: nix flake check ./example --no-write-lock-file --override-input nix-config "git+file://$(pwd | sed -e 's/\s/%20/g')?shallow=1"