Add GitHub Actions to test compilation

.github/workflows/test-pixi.yaml

@@ -0,0 +1,32 @@
+name: Run tests with pixi
+
+on:
+  workflow_dispatch:
+  pull_request:
+
+jobs:
+  pixi-test:
+    name: '[pixi:${{ matrix.os }}]'
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [
+          ubuntu-22.04,
+          macos-latest,
+          windows-2019
+        ]
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up pixi
+      uses: prefix-dev/[email protected]
+      with:
+        run-install: true
+        cache: false
+
+    - name: Print pixi info
+      run: pixi info
+
+    - name: Build and test the project
+      run: pixi run test

.github/workflows/update-pixi-lockfile.yaml

@@ -0,0 +1,42 @@
+name: Update lockfiles
+
+permissions:
+  contents: write
+  pull-requests: write
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: 0 5 1 * *
+
+jobs:
+  pixi-update:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up pixi
+        uses: prefix-dev/[email protected]
+        with:
+          run-install: false
+
+      - name: Install pixi-diff-to-markdown
+        run: pixi global install pixi-diff-to-markdown
+
+      - name: Update lockfiles
+        run: |
+          set -o pipefail
+          pixi update --json | pixi exec pixi-diff-to-markdown >> diff.md
+
+      - name: Create pull request
+        uses: peter-evans/create-pull-request@v6
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          commit-message: Update pixi lockfile
+          title: Update pixi lockfile
+          body-path: diff.md
+          branch: update-pixi
+          base: main
+          labels: pixi
+          delete-branch: true
+          add-paths: pixi.lock