Bump cachix/install-nix-action from 25 to 26

Bumps [cachix/install-nix-action](https://github.com/cachix/install-nix-action) from 25 to 26.
- [Release notes](https://github.com/cachix/install-nix-action/releases)
- [Commits](cachix/install-nix-action@v25...v26)

---
updated-dependencies:
- dependency-name: cachix/install-nix-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/netlify.yml

@@ -16,7 +16,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install Nix
-        uses: cachix/install-nix-action@v25
+        uses: cachix/install-nix-action@v26
         with:
           github_access_token: ${{ secrets.GITHUB_TOKEN }}