chore: bump DeterminateSystems/magic-nix-cache-action from 4 to 6

Bumps [DeterminateSystems/magic-nix-cache-action](https://github.com/determinatesystems/magic-nix-cache-action) from 4 to 6.
- [Release notes](https://github.com/determinatesystems/magic-nix-cache-action/releases)
- [Commits](DeterminateSystems/magic-nix-cache-action@fc6aace...87e8236)

---
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/ci.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@fc6aaceb40b9845a02b91e059ec147e78d1b4e41 # v4
+        uses: DeterminateSystems/magic-nix-cache-action@87e8236f46702ab0ce5a058b605a173ec88d618e # v6
 
       - name: Set up Go cache
         uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
@@ -84,7 +84,7 @@ jobs:
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
 
       - name: Set up magic Nix cache
-        uses: DeterminateSystems/magic-nix-cache-action@fc6aaceb40b9845a02b91e059ec147e78d1b4e41 # v4
+        uses: DeterminateSystems/magic-nix-cache-action@87e8236f46702ab0ce5a058b605a173ec88d618e # v6
 
       - name: Set up Go cache
         uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
@@ -117,7 +117,7 @@ jobs:
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
 
       - name: Set up magic Nix cache
-        uses: DeterminateSystems/magic-nix-cache-action@fc6aaceb40b9845a02b91e059ec147e78d1b4e41 # v4
+        uses: DeterminateSystems/magic-nix-cache-action@87e8236f46702ab0ce5a058b605a173ec88d618e # v6
 
       - name: Set up Go cache
         uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
@@ -150,7 +150,7 @@ jobs:
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
 
       - name: Set up magic Nix cache
-        uses: DeterminateSystems/magic-nix-cache-action@fc6aaceb40b9845a02b91e059ec147e78d1b4e41 # v4
+        uses: DeterminateSystems/magic-nix-cache-action@87e8236f46702ab0ce5a058b605a173ec88d618e # v6
 
       - name: Set up Go cache
         uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
@@ -200,7 +200,7 @@ jobs:
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
 
       - name: Set up magic Nix cache
-        uses: DeterminateSystems/magic-nix-cache-action@fc6aaceb40b9845a02b91e059ec147e78d1b4e41 # v4
+        uses: DeterminateSystems/magic-nix-cache-action@87e8236f46702ab0ce5a058b605a173ec88d618e # v6
 
       - name: Check
         run: nix flake check --impure
@@ -269,7 +269,7 @@ jobs:
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
 
       - name: Set up magic Nix cache
-        uses: DeterminateSystems/magic-nix-cache-action@fc6aaceb40b9845a02b91e059ec147e78d1b4e41 # v4
+        uses: DeterminateSystems/magic-nix-cache-action@87e8236f46702ab0ce5a058b605a173ec88d618e # v6
 
       - name: Set up Go cache
         uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2