Enhance Python package workflow for new Python version

Updated Python CI workflow to support Python 3.12, added build step, and improved dependency installation.

Author: andyjiayuwang

.github/workflows/python-package.yml

@@ -0,0 +1,88 @@
+name: Python package
+
+on:
+  push:
+    branches: ["main"]
+  pull_request:
+    branches: ["main"]
+  release:
+    types: [published]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.10", "3.11", "3.12"]
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v5
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v6
+        with:
+          python-version: ${{ matrix.python-version }}
+          cache: pip
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install build flake8 pytest
+          python -m pip install .
+
+      - name: Lint with flake8
+        run: |
+          flake8 src --count --select=E9,F63,F7,F82 --show-source --statistics
+          flake8 src --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+
+      - name: Test with pytest
+        run: |
+          if [ -d tests ]; then
+            pytest -q
+          else
+            echo "No tests directory found, skipping pytest."
+          fi
+
+      - name: Build package
+        run: python -m build
+
+  publish:
+    if: github.event_name == 'release'
+    needs: test
+    runs-on: ubuntu-latest
+    environment:
+      name: pypi
+      url: https://pypi.org/p/rlearner
+    permissions:
+      contents: read
+      id-token: write
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v5
+
+      - name: Set up Python 3.12
+        uses: actions/setup-python@v6
+        with:
+          python-version: "3.12"
+          cache: pip
+
+      - name: Install build tools
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install build twine
+
+      - name: Build distribution
+        run: python -m build
+
+      - name: Check distribution
+        run: twine check dist/*
+
+      - name: Publish to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1