Merge 868ad84fb8 into 44419a52d6

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/ci.yml

@@ -17,7 +17,7 @@ jobs:
         with:
           tool-cache: true
       - uses: DeterminateSystems/magic-nix-cache-action@v8
-      - uses: cachix/cachix-action@v15
+      - uses: cachix/cachix-action@v16
         with:
           name: callumio-public
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'