DRAFT: GitHub Actions: Test on Python 3.13 beta release

https://www.python.org/downloads/release/python-3130b1/

Like:
* #9306
* #8777
* #6591
* #5992
* #4396
* #3926
* #2279

Author: cclauss

Diff for: .github/workflows/build.yml

@@ -12,7 +12,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: 3.12
+          python-version: 3.13
           allow-prereleases: true
       - uses: actions/cache@v4
         with: