fix: update SDK submodule with portable Python bundling for commit0

Update SDK submodule to include the Python runtime bundling fix
(OpenHands/software-agent-sdk#2678). The agent-server Dockerfile now
bundles Python into /agent-server/.python/, making the venv portable
across base images.

This fixes commit0 evaluations where all runtime pods were stuck in
pending because the agent-server container couldn't start — the venv
symlinked to /usr/local/bin/python3 which doesn't exist in commit0's
Ubuntu 22.04 base images.

Fixes #607

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Debug Agent