build(deps): bump cachix/install-nix-action from 25 to 26 (#7)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/gh-pages.yaml

@@ -24,7 +24,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install Nix
-        uses: cachix/install-nix-action@v25
+        uses: cachix/install-nix-action@v26
 
       - name: Build docs
         run: nix build .#options-doc

.github/workflows/update-flakes.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: cachix/install-nix-action@v25
+      - uses: cachix/install-nix-action@v26
       - uses: DeterminateSystems/update-flake-lock@v21
         with:
           token: ${{ secrets.GH_TOKEN_FOR_UPDATES }}