ci: cache pixi packages on push to main

.github/workflows/ci.yml

@@ -21,6 +21,20 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  cache:
+    if: ${{ github.event_name == 'push' && github.ref_name == 'main' }}
+    runs-on: windows-latest
+    strategy:
+      matrix:
+        pixi_env: [audio, arithmetic]
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up pixi
+        uses: prefix-dev/[email protected]
+        with:
+          environments: ${{matrix.pixi_env}}
+          cache: true
+
   ruff-lint:
     uses: Glatzel/template/.github/workflows/ruff.yml@main
 
@@ -29,7 +43,6 @@ jobs:
     with:
       name: test
       machine: windows-latest
-      cache_write: ${{ github.event_name == 'push' && github.ref_name == 'main' }}
       pixi_python_env: audio
       test_path: ./src/audio
       update_submodule: true
@@ -42,7 +55,6 @@ jobs:
     with:
       name: test
       machine: windows-latest
-      cache_write: ${{ github.event_name == 'push' && github.ref_name == 'main' }}
       pixi_python_env: arithmetic-cpu
       test_path: ./src/arithmetic
       update_submodule: true