chore(deps): bump DeterminateSystems/nix-installer-action from 7 to 9 (#15)

Bumps [DeterminateSystems/nix-installer-action](https://github.com/determinatesystems/nix-installer-action) from 7 to 9.
- [Release notes](https://github.com/determinatesystems/nix-installer-action/releases)
- [Commits](https://github.com/determinatesystems/nix-installer-action/compare/v7...v9)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/test.yml

@@ -28,7 +28,7 @@ jobs:
         run: pnpm install && pnpm build
 
       - name: Install Nix
-        uses: DeterminateSystems/nix-installer-action@v7
+        uses: DeterminateSystems/nix-installer-action@v9
 
       - name: Setup Attic Cache
         uses: ./