Fix lychee caching

.github/workflows/link-checker.yaml

@@ -22,18 +22,24 @@ jobs:
   link-checker:
     runs-on: ubuntu-latest
     steps:
-      - name: Restore lychee cache
-        uses: actions/cache@v4
-        with:
-          path: .lycheecache
-          key: cache-lychee-${{ github.sha }}
-          restore-keys: cache-lychee-
       - uses: actions/checkout@v4
       - uses: DeterminateSystems/nix-installer-action@v14
       - uses: DeterminateSystems/magic-nix-cache-action@v8
+      - name: Restore lychee cache
+        id: cache-lychee-restore
+        uses: actions/cache/restore@v4
+        with:
+          key: lychee-cache
+          path: .lycheecache
       - name: Convert the Asciidoc files to html
         run: nix develop --command asciidoctor ./**/*.adoc
       - name: Run lychee on the generated site
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: nix develop --command lychee --cache --no-progress --verbose ./**/*.html
+      - name: Save lychee cache
+        uses: actions/cache/save@v4
+        if: always()
+        with:
+          key: lychee-ccache
+          path: .lycheecache