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](cachix/cachix-action@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>

Author: dependabot[bot]

.github/workflows/release.yml

@@ -18,7 +18,7 @@ jobs:
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
-      - uses: cachix/cachix-action@v15
+      - uses: cachix/cachix-action@v16
         if: ${{ steps.release.outputs.release_created }}
         with:
           name: klarkc

.github/workflows/test.yml

@@ -10,7 +10,7 @@ jobs:
       with:
         extra_nix_config: |
           access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
-    - uses: cachix/cachix-action@v15
+    - uses: cachix/cachix-action@v16
       with:
         name: klarkc
         authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'

.github/workflows/update-flake-lock.yml

@@ -15,7 +15,7 @@ jobs:
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
-      - uses: cachix/cachix-action@v15
+      - uses: cachix/cachix-action@v16
         with:
           name: klarkc
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'