[CHORE] Split Python tests that run on main so half run on mcmr.

[rescrv]

Description of changes

We want to test multi-cloud, multi-region without doubling CI wait times
or the overall sum of CPU consumed. The fix is simple: We already run
multiple Python versions, so run half of them on mcmr and half on the
classic tilt file.

Test plan

CI will be the test.

Migration plan

N/A

Observability plan

Watch CI on landing.

Documentation Changes

N/A

[github-actions]

Reviewer Checklist

Please leverage this checklist to ensure your code review is thorough before approving

Testing, Bugs, Errors, Logs, Documentation

• Can you think of any use case in which the code does not behave as intended? Have they been tested?
• Can you think of any inputs or external events that could break the code? Is user input validated and safe? Have they been tested?
• If appropriate, are there adequate property based tests?
• If appropriate, are there adequate unit tests?
• Should any logging, debugging, tracing information be added or removed?
• Are error messages user-friendly?
• Have all documentation changes needed been made?
• Have all non-obvious changes been commented?

System Compatibility

• Are there any potential impacts on other parts of the system or backward compatibility?
• Does this change intersect with any items on our roadmap, and if so, is there a plan for fitting them together?

Quality

• Is this code of a unexpectedly high quality (Readability, Modularity, Intuitiveness)

[propel-code-bot]

The release workflow now divides the Linux Python matrix into two complementary jobs, keeping 3.9/3.11 on the classic runners while routing 3.10/3.12 through the multi-cloud multi-region path, and the shared _python-tests.yml workflow surfaces an always_multi_region input so the cluster frontend can set MULTI_REGION when either the caller or the matrix requests it.

Affected Areas

• .github/workflows/release-chromadb.yml
• .github/workflows/_python-tests.yml

This summary was automatically generated by @propel-code-bot

[propel-code-bot]

[Logic] workflow_call inputs must be declared as mapping objects; assigning always_multi_region: false leaves the input undefined and causes fromJson(inputs.always_multi_region) to fail. Define this input like the others (description, type, default) and keep the value as a JSON array string so callers can pass '[false]' or '[true]' as needed.

Context for Agents

`workflow_call` inputs must be declared as mapping objects; assigning `always_multi_region: false` leaves the input undefined and causes `fromJson(inputs.always_multi_region)` to fail. Define this input like the others (description, type, default) and keep the value as a JSON array string so callers can pass `'[false]'` or `'[true]'` as needed.

File: .github/workflows/_python-tests.yml
Line: 20

[rescrv]

We did something different to test pre-merge on 3.9.