Upgrade python for Certora CI

Author: sunbreak1211

.github/workflows/certora.yml

@@ -23,10 +23,10 @@ jobs:
           java-version: '11'
           java-package: jre
 
-      - name: Set up Python 3.8
-        uses: actions/setup-python@v3
+      - name: Set up Python 3.13
+        uses: actions/setup-python@v5
         with:
-          python-version: 3.8
+          python-version: '3.13'
 
       - name: Install solc-select
         run: pip3 install solc-select