Bump DeterminateSystems/magic-nix-cache-action from 6 to 7

Bumps [DeterminateSystems/magic-nix-cache-action](https://github.com/determinatesystems/magic-nix-cache-action) from 6 to 7.
- [Release notes](https://github.com/determinatesystems/magic-nix-cache-action/releases)
- [Commits](DeterminateSystems/magic-nix-cache-action@87e8236...b46e247)

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

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

.github/workflows/generate.yaml

@@ -28,7 +28,7 @@ jobs:
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
 
       - name: Set up magic Nix cache
-        uses: DeterminateSystems/magic-nix-cache-action@87e8236f46702ab0ce5a058b605a173ec88d618e # v6
+        uses: DeterminateSystems/magic-nix-cache-action@b46e247b898aa56e6d2d2e728dc6df6c84fdb738 # v7
 
       - name: Prepare Nix shell
         run: nix develop --impure .#ci