ci: try caching again (#50)

Author: henryiii

.github/workflows/cd.yml

@@ -21,10 +21,9 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: prefix-dev/setup-pixi@v0.5.1
+      - uses: prefix-dev/setup-pixi@v0.8.0
         with:
-          pixi-version: v0.17.1
-          cache: false
+          pixi-version: v0.22.0
 
       - name: Build the book
         run: pixi run book