Resolve OOM failures in auto-devops/python-tox.yml jobs

Summary

After migrating the jobs in the auto-devops/python-tox.yml template to the GKE-based devops-general runner, we have observed OOM failures in some jobs. This issue involves profiling these jobs to determine an appropriate memory limit and updating the template to set the limit using the KUBERNETES_MEMORY_LIMIT variable.

Acceptance criteria

• All jobs in the auto-devops/python-tox.yml template run successfully on the devops-general runner.