ci: change python version in update_regression_baselines.yaml to use python 3.13

Author: harryswift01

.github/workflows/update_regression_baselines.yaml

@@ -25,7 +25,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
-          python-version: "3.14"
+          python-version: "3.13"
           cache: pip
 
       - name: Install testing dependencies