Bump cachix/install-nix-action from 23 to 25

Bumps [cachix/install-nix-action](https://github.com/cachix/install-nix-action) from 23 to 25.
- [Release notes](https://github.com/cachix/install-nix-action/releases)
- [Commits](https://github.com/cachix/install-nix-action/compare/v23...v25)

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

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

.github/workflows/ci.yml

@@ -33,7 +33,7 @@ jobs:
           components: rustfmt
           profile: minimal
           toolchain: nightly
-      - uses: cachix/install-nix-action@v23
+      - uses: cachix/install-nix-action@v25
         if: ${{ matrix.os != 'windows-latest' }}
         with:
           nix_path: nixpkgs=channel:nixos-unstable