Add correctness check via CI

Author: felsenhower

.github/workflows/correctness_check.yaml

@@ -0,0 +1,45 @@
+name: Correctness Check
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  build-test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Valgrind
+        run: sudo apt-get update && sudo apt-get install -y valgrind
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v6
+        with:
+          version: "0.9.8"
+
+      - name: Set up Python
+        run: uv python install
+
+      - name: Clone partdiff_tester
+        run: git clone https://github.com/parcio/partdiff_tester.git
+
+      - name: Run small correctness check subset with valgrind
+        run: |
+          cd partdiff_tester && \
+          uv run pytest -n auto --verbose \
+            --executable='../partdiff' \
+            --strictness=4 \
+            --valgrind \
+            --shuffle=42 \
+            --max-num-tests=5
+
+      - name: Run correctness check
+        run: |
+          cd partdiff_tester && \
+          uv run pytest -n auto --verbose \
+            --executable='../partdiff' \
+            --strictness=4 \
+            --shuffle=42