Bump cachix/cachix-action from 11 to 12

Bumps [cachix/cachix-action](https://github.com/cachix/cachix-action) from 11 to 12.
- [Release notes](https://github.com/cachix/cachix-action/releases)
- [Commits](https://github.com/cachix/cachix-action/compare/v11...v12)

---
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

@@ -11,7 +11,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: cachix/install-nix-action@v18
       - name: Cachix
-        uses: cachix/cachix-action@v11
+        uses: cachix/cachix-action@v12
         with:
           name: chvp
           extraPullNames: "nix-community,accentor"

.github/workflows/update.yml

@@ -12,7 +12,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: cachix/install-nix-action@v18
       - name: Cachix
-        uses: cachix/cachix-action@v11
+        uses: cachix/cachix-action@v12
         with:
           name: chvp
           extraPullNames: "nix-community,accentor"