fix failing test cases in the pipeline

Author: Bavneet Singh

testing/pipeline/k8s-custom-pipelines.yml

@@ -140,12 +140,14 @@ stages:
       vmImage: 'ubuntu-latest'
     strategy:
       matrix:
-        Python38:
-          python.version: '3.8'
         Python39:
           python.version: '3.9'
         Python310:
           python.version: '3.10'
+        Python311:
+          python.version: '3.11'
+        Python312:
+          python.version: '3.12'
     steps:
       - task: UsePythonVersion@0
         displayName: 'Use Python $(python.version)'