chore(deps): bump cachix/cachix-action from 13 to 15

Bumps [cachix/cachix-action](https://github.com/cachix/cachix-action) from 13 to 15.
- [Release notes](https://github.com/cachix/cachix-action/releases)
- [Commits](cachix/cachix-action@v13...v15)

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

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

.github/workflows/deploy.yaml

@@ -28,7 +28,7 @@ jobs:
           extra_nix_config: "extra-experimental-features = nix-command flakes"
 
       - name: Set up cachix
-        uses: cachix/cachix-action@v13
+        uses: cachix/cachix-action@v15
         with:
           name: tie-infra
           authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}

.github/workflows/installer.yaml

@@ -15,7 +15,7 @@ jobs:
           extra_nix_config: "extra-experimental-features = nix-command flakes"
 
       - name: Set up cachix
-        uses: cachix/cachix-action@v13
+        uses: cachix/cachix-action@v15
         with:
           name: tie-infra
           authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}

.github/workflows/update.yaml

@@ -16,7 +16,7 @@ jobs:
           extra_nix_config: "extra-experimental-features = nix-command flakes"
 
       - name: Set up cachix
-        uses: cachix/cachix-action@v13
+        uses: cachix/cachix-action@v15
         with:
           name: tie-infra
           authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}