build(deps): bump cachix/cachix-action from 15 to 16

Bumps [cachix/cachix-action](https://github.com/cachix/cachix-action) from 15 to 16.
- [Release notes](https://github.com/cachix/cachix-action/releases)
- [Commits](https://github.com/cachix/cachix-action/compare/v15...v16)

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

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/cachix.yml

@@ -36,7 +36,7 @@ jobs:
       - name: Install Nix
         uses: DeterminateSystems/nix-installer-action@main
 
-      - uses: cachix/cachix-action@v15
+      - uses: cachix/cachix-action@v16
         with:
           authToken: ${{ secrets.CACHIX_TOKEN }}
           extraPullNames: nix-community