Add 3.13 to basepython

Author: sentrivana

tox.ini

@@ -766,13 +766,14 @@ basepython =
     py3.10: python3.10
     py3.11: python3.11
     py3.12: python3.12
+    py3.13: python3.13
 
     # Python version is pinned here because flake8 actually behaves differently
     # depending on which version is used. You can patch this out to point to
     # some random Python 3 binary, but then you get guaranteed mismatches with
     # CI. Other tools such as mypy and black have options that pin the Python
     # version.
-    linters: python3.12
+    linters: python3.13
 
 commands =
     {py3.7,py3.8}-boto3: pip install urllib3<2.0.0