Move Nix flake to repo root - #12

Failed to save: <h2>Our services aren't available right now</h2><p>We're working to restore all services as soon as possible. Please check back soon.</p>0iCdcaQAAAACdtgxOjKGdTK8RO5gQHZIhQ0hJMzBFREdFMDQxNgBFZGdl

Failed to restore: Cache service responded with 400

Magic Nix Cache has been deprecated due to a change in the underlying GitHub APIs and will stop working on 1 February 2025. To continue caching Nix builds in GitHub Actions, use FlakeHub Cache instead. Replace... uses: DeterminateSystems/magic-nix-cache-action@v9 ...with... uses: DeterminateSystems/flakehub-cache-action@v9 For more details: https://dtr.mn/magic-nix-cache-eol

Magic Nix Cache has been deprecated due to a change in the underlying GitHub APIs and will stop working on 1 February 2025. To continue caching Nix builds in GitHub Actions, use FlakeHub Cache instead. Replace... uses: DeterminateSystems/magic-nix-cache-action@v9 ...with... uses: DeterminateSystems/flakehub-cache-action@v9 For more details: https://dtr.mn/magic-nix-cache-eol