Install Python 3.13 to fix failing PR checks with older CLI versions

[mbg]

Some of our PR checks are currently failing due to an incompatibility between older CLI versions and Python 3.14. The problem is fixed in nightly-latest, but older CLI releases need Python 3.13 or below.

This PR updates sync.py to support an installPython option in workflow templates. I have set this option to true for all PR checks that run a Python analysis.

Risk assessment

For internal use only. Please select the risk level of this change:

• Low risk: Changes are fully under feature flags, or have been fully tested and validated in pre-production environments and are highly observable, or are documentation or test only.

Which use cases does this change impact?

CI only.

How did/will you validate this change?

• End-to-end tests - I am depending on PR checks (i.e. tests in pr-checks).

If something goes wrong after this change is released, what are the mitigation and rollback strategies?

CI only.

How will you know if something goes wrong after this change is released?

CI will continue to fail.

Merge / deployment checklist

• Confirm this change is backwards compatible with existing workflows.
• Consider adding a changelog entry for this change.
• Confirm the readme and docs have been updated if necessary.

[Copilot]

Pull Request Overview

This PR adds Python 3.13 installation support to fix failing PR checks that were caused by an incompatibility between older CLI versions and Python 3.14. The solution implements an installPython option in workflow templates that installs Python 3.13 for all versions except nightly-latest.

• Adds Python installation infrastructure to the sync.py script
• Enables Python installation for all PR check workflows that perform Python analysis
• Generates corresponding workflow files with Python setup steps

Reviewed Changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated no comments.

File	Description
pr-checks/sync.py	Implements installPython option support and Python 3.13 installation logic
pr-checks/checks/*.yml	Enables installPython: true for various test workflows
.github/workflows/__*.yml	Generated workflow files with Python installation steps