Bump DeterminateSystems/flake-checker-action from 7 to 8

Bumps [DeterminateSystems/flake-checker-action](https://github.com/determinatesystems/flake-checker-action) from 7 to 8.
- [Release notes](https://github.com/determinatesystems/flake-checker-action/releases)
- [Commits](DeterminateSystems/flake-checker-action@v7...v8)

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

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

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
           ref: ${{ github.event.pull_request.head.ref }}
           submodules: true
 
-      - uses: DeterminateSystems/flake-checker-action@v7
+      - uses: DeterminateSystems/flake-checker-action@v8
 
       - uses: DeterminateSystems/nix-installer-action@main
       - uses: DeterminateSystems/magic-nix-cache-action@main