GitHub Actions: Add Python 3.13 to the testing

Author: cclauss

.github/workflows/ci.yml

@@ -68,7 +68,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-13, macos-latest]
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12', '3.13']
         exclude:
           # Python 3.8 and 3.9 are not available on macOS 14
           - os: macos-13
@@ -77,6 +77,8 @@ jobs:
             python-version: '3.11'
           - os: macos-13
             python-version: '3.12'
+          - os: macos-13
+            python-version: '3.13'
           - os: macos-latest
             python-version: '3.8'
           - os: macos-latest
@@ -104,8 +106,8 @@ jobs:
       # display coverage and fail if it's below 80%, which shouldn't happen
       - run: coverage report --fail-under=80
 
-      # test demo on 3.11 and 3.12, these tests are intentionally omitted from coverage
-      - if: matrix.python-version == '3.11' || matrix.python-version == '3.12'
+      # test demo on >= 3.11, these tests are intentionally omitted from coverage
+      - if: matrix.python-version == '3.11' || matrix.python-version == '3.12' || matrix.python-version == '3.13'
         run: pytest demo/tests.py
 
       - run: coverage xml
@@ -157,7 +159,7 @@ jobs:
         with:
           python-version: '3.11'
 
-      - run: pip install -U build
+      - run: pip install --upgrade build
 
       - id: check-version
         uses: samuelcolvin/check-python-version@v4.1