ci: Publish distribution files to PyPI

Add steps to publish distribution files to PyPI when a tag is created.

The Python version used to create the wheel is updated just for
consistency with other projects, it shouldn't really affect the
resulting wheel because this is a pure python package, so it doesn't
depend on the Python version, is just shipping text files.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

.github/workflows/ci.yaml

@@ -34,42 +34,51 @@ jobs:
       - name: Install required Python packages
         run: |
           python -m pip install --upgrade pip
-          python -m pip install nox wheel
+          python -m pip install nox
 
       - name: run nox
         run: nox -e ci_checks_max pytest_min
         timeout-minutes: 10
 
-  build-wheels:
+  build-dist:
     runs-on: ubuntu-20.04
-    needs: test
-
     steps:
-    - name: Fetch sources
-      uses: actions/checkout@v3
+      - name: Fetch sources
+        uses: actions/checkout@v3
 
-    - name: Set up Python
-      uses: actions/setup-python@v4
-      with:
-        python-version: 3.8
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: "3.10"
 
-    - uses: actions/cache@v3
-      with:
-        path: ~/.cache/pip
-        key: ${{ runner.os }}-${{ matrix.python-version }}-pip-${{ hashFiles('minimum-requirements-ci.txt', 'pyproject.toml') }}
-        restore-keys: |
-          ${{ runner.os }}-${{ matrix.python-version }}-pip-
+      - name: Install build dependencies
+        run: |
+          python -m pip install -U pip
+          python -m pip install -U build
 
-    - name: Install required Python packages
-      run: |
-        python -m pip install --upgrade pip
-        python -m pip install wheel
+      - name: Build the source and binary distribution
+        run: python -m build
 
-    - name: make wheel
-      run: python -m pip wheel --no-deps -w dist .
+      - name: Upload dist files
+        uses: actions/upload-artifact@v3
+        with:
+          name: frequenz-sdk-python-dist
+          path: dist/
+          if-no-files-found: error
+
+  publish-to-pypi:
+    needs: ["test", "build-dist"]
+    # Publish only on tags creation
+    if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags')
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Download dist files
+        uses: actions/download-artifact@v3
+        with:
+          name: frequenz-sdk-python-dist
 
-    - name: upload wheels
-      uses: actions/upload-artifact@v3
-      with:
-        name: frequenz-sdk-python-wheels
-        path: dist/*.whl
+      - name: Publish the Python distribution to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          password: ${{ secrets.PYPI_API_TOKEN }}
+          skip_existing: true