Update beam-master images for python sdks (#36699)

Author: shunping

sdks/python/apache_beam/runners/dataflow/internal/names.py

@@ -34,6 +34,6 @@
 # Unreleased sdks use container image tag specified below.
 # Update this tag whenever there is a change that
 # requires changes to SDK harness container or SDK harness launcher.
-BEAM_DEV_SDK_CONTAINER_TAG = 'beam-master-20251020'
+BEAM_DEV_SDK_CONTAINER_TAG = 'beam-master-20251031'
 
 DATAFLOW_CONTAINER_IMAGE_REPOSITORY = 'gcr.io/cloud-dataflow/v1beta3'