Run Python SDK tests in CI

Add a separate Python SDK runner that installs the pinned musl runtime wheel in an Alpine Python container and runs the SDK pytest suite in parallel with existing SDK checks.

Co-authored-by: Codex <noreply@openai.com>

.github/workflows/sdk.yml

@@ -6,6 +6,37 @@ on:
   pull_request: {}
 
 jobs:
+  python-sdk:
+    runs-on:
+      group: codex-runners
+      labels: codex-linux-x64
+    timeout-minutes: 10
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          ref: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
+          persist-credentials: false
+
+      - name: Test Python SDK
+        shell: bash
+        run: |
+          set -euo pipefail
+
+          docker run --rm \
+            --user "$(id -u):$(id -g)" \
+            -e HOME=/tmp/codex-python-sdk-home \
+            -e UV_LINK_MODE=copy \
+            -v "${GITHUB_WORKSPACE}:${GITHUB_WORKSPACE}" \
+            -w "${GITHUB_WORKSPACE}/sdk/python" \
+            python:3.12-alpine \
+            sh -euxc '
+              python -m venv /tmp/uv
+              /tmp/uv/bin/python -m pip install uv==0.11.3
+              /tmp/uv/bin/uv sync --extra dev --frozen
+              /tmp/uv/bin/uv run --extra dev pytest
+            '
+
   sdks:
     runs-on:
       group: codex-runners