chores: init ci workflow

fix: do pixi install before running tests

.github/workflows/ci.yaml

@@ -0,0 +1,18 @@
+name: ci
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: prefix-dev/[email protected]
+        with:
+          pixi-version: v0.39.4
+          cache: true
+      - run: pixi run test