ci: Use Python 3.13 release version for testing.

Author: seifertm

.github/workflows/main.yml

@@ -62,7 +62,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu, windows]
-        python-version: ['3.9', '3.10', '3.11', '3.12', 3.13.0-beta.3]
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
 
     steps:
     - uses: actions/checkout@v4