Add CI workflows for build testing and PyPI publishing

- build.yml: Test building on Python 3.10-3.13, verify installation
- publish.yml: Publish to PyPI on GitHub releases using trusted publishing

Author: skef

.github/workflows/build.yml

@@ -0,0 +1,49 @@
+name: Build and Test
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    name: Build on Python ${{ matrix.python-version }}
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ['3.10', '3.11', '3.12', '3.13']
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - name: Install build dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install build twine
+
+    - name: Build package
+      run: python -m build
+
+    - name: Check distribution
+      run: twine check dist/*
+
+    - name: Install from wheel
+      run: pip install dist/*.whl
+
+    - name: Verify installation
+      run: |
+        python -c "import skbuild_conditional_scripts; print('Package imported successfully')"
+        python -c "from skbuild_conditional_scripts import dynamic_metadata; print('Function imported successfully')"
+
+    - name: Upload artifacts
+      if: matrix.python-version == '3.12'
+      uses: actions/upload-artifact@v4
+      with:
+        name: distributions
+        path: dist/

.github/workflows/publish.yml

@@ -0,0 +1,33 @@
+name: Publish to PyPI
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  build-and-publish:
+    name: Build and publish to PyPI
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write  # Required for trusted publishing
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
+
+    - name: Install build dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install build
+
+    - name: Build package
+      run: python -m build
+
+    - name: Publish to PyPI
+      uses: pypa/gh-action-pypi-publish@release/v1
+      # This uses PyPI's trusted publisher (no token needed)
+      # Configure at: https://pypi.org/manage/account/publishing/