Remove sparse checkout

Author: VeckoTheGecko

.github/workflows/cache-pixi-lock.yml

@@ -17,7 +17,6 @@ jobs:
       - uses: actions/checkout@v5
         with:
           fetch-depth: 0
-          sparse-checkout: pixi.toml
       - name: Get current date
         id: date
         run: echo "date=$(date +'%Y-%m-%d')" >> "$GITHUB_OUTPUT"