CI: Add python 3.13.0-rc.3 (currently a pre-release).

Author: jenisys

.github/workflows/test.yml

@@ -20,7 +20,7 @@ jobs:
       matrix:
         # PREPARED: os: [ubuntu-latest, macos-latest, windows-latest]
         os: [ubuntu-latest, windows-latest]
-        python-version: ["3.12", "3.11", "3.10"]
+        python-version: ["3.13.0-rc.3", "3.12", "3.11", "3.10"]
         exclude:
           - os: windows-latest
             python-version: "2.7"