Remove pin on Python 3.13 version (#1775)

We'd pinned Python 3.13 to avoid an issue on Windows with the 3.13.0a4
build.

Now that 3.13.0a5 is available, that issue should be resolved, so that
we can remove the pin.

.github/workflows/run-core-traits-tests.yml

@@ -11,7 +11,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest]
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12', '3.13.0-alpha.3']
+        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12', '3.13']
 
     runs-on: ${{ matrix.os }}