Bump the actions group with 1 update

Bumps the actions group with 1 update: [cachix/install-nix-action](https://github.com/cachix/install-nix-action).


Updates `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
  dependency-group: actions
...

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

.github/workflows/build.yml

@@ -21,7 +21,7 @@ jobs:
           submodules: true
       - run: sudo apt-get update && sudo apt-get install -y qemu-user-static
       - name: Setup Nix
-        uses: cachix/install-nix-action@v25
+        uses: cachix/install-nix-action@v26
         with:
           github_access_token: ${{ secrets.GITHUB_TOKEN }}
           extra_nix_config: |