ci: Nighly tests against latest polars versions

.github/workflows/nightly.yml

@@ -0,0 +1,38 @@
+name: Nightly
+on:
+  schedule:
+    - cron: "0 0 * * *"
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  unit-tests:
+    name: pytest (Polars prerelease)
+    timeout-minutes: 30
+    runs-on: ${{ matrix.os }}
+    permissions:
+      contents: read
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - ubuntu-latest
+          - windows-latest
+    steps:
+      - name: Check out branch
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - name: Set up pixi
+        uses: prefix-dev/setup-pixi@f00437f565399d418b0acc85936d12c1fb668347 # v0.10.1
+        with:
+          environments: nightly
+      - name: Install latest Polars including prereleases
+        run: pixi run -e nightly install-polars-nightly
+      - name: Show Polars version
+        run: pixi run -e nightly python -c "import polars as pl; print(pl.__version__)"
+      - name: Install repository
+        run: pixi run -e nightly postinstall
+      - name: Run pytest
+        run: pixi run -e nightly test-coverage --color=yes