WIP: Update Python to the latest release, since some newer packages, like pandas,...

What does this MR do?

Some newer packages, like Pandas, do not support Python 3.6 any more, which makes this tool fail silently. This MR updates the version of Python to the latest release to accommodate for that.

What are the relevant issue numbers?

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Auto-DevOps template
  • Job definition example
  • CI Templates
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer