build(deps): bump DeterminateSystems/flake-checker-action from 8 to 9

Bumps [DeterminateSystems/flake-checker-action](https://github.com/determinatesystems/flake-checker-action) from 8 to 9.
- [Release notes](https://github.com/determinatesystems/flake-checker-action/releases)
- [Commits](https://github.com/determinatesystems/flake-checker-action/compare/v8...v9)

---
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/flake.yml

@@ -32,7 +32,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Check Nix flake inputs
-        uses: DeterminateSystems/flake-checker-action@v8
+        uses: DeterminateSystems/flake-checker-action@v9
 
   check:
     name: Check Nix Flake