Bump cachix/install-nix-action from V27 to 30

Bumps [cachix/install-nix-action](https://github.com/cachix/install-nix-action) from V27 to 30. This release includes the previously tagged commit.
- [Release notes](https://github.com/cachix/install-nix-action/releases)
- [Commits](cachix/install-nix-action@V27...v30)

---
updated-dependencies:
- dependency-name: cachix/install-nix-action
  dependency-type: direct:production
...

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

.github/workflows/ci.yml

@@ -50,7 +50,7 @@ jobs:
 
       - name: Set up nix
         if: matrix.type == 'dapp'
-        uses: cachix/install-nix-action@V27
+        uses: cachix/install-nix-action@v30
 
       - name: Set up cachix
         if: matrix.type == 'dapp'