Modified files to reduce resources requested by LBC rose stem tasks

[mo-rickywong]

Description

Core rose stem test suite contains LBC task that are requesting significant resource. This was reviewed and reduced to something more sensible.

Linked issues

None- This is a straight LFRic core ticket

Resolve Lfric trac ticket #4706

Developer tags

N/A

Type of change

Resource reduction, does change the KGOs of a couple of tasks as the domain decomposition changes on the LBC tasks

How has this been tested?

Core Rose test-suite ran with updated files/KGOs, all green and better time to completion.

• New tests have been added.
• Tests have been modified to accommodate this change.
• GitHub workflows have been changed or added.

Checklist:

• The change has been checked for design compliance by an experienced SSE
• My code follows the style guidelines of this project.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes, for both debug and optimised builds.
• No AI tools have been used in the creation of this change.

Reasoning on why any of the above boxes have not been checked

Some of the checklist items are not applicable

Review Checks (To be filled in by the reviewer/s)

• Has the developer completed the appropriate sections above?
• Is the change compliant with LFRic Core principles?
• Is the testing coverage sufficient?
• Have any technical debt workarounds identified had issues opened and interested parties notified?

[james-bruten-mo]

Looks sensible to me, and I can see your tests passing which are up to date with main