feat: Add and use sub-slicing topology during Kueue configuration

[jamOne-]

Fixes / Features

• Add and use sub-slicing topology during Kueue configuration (http://b/452626879).
• I omitted the NoSchedule TPU toleration, because I'm not convinced it's required. We'll revisit this later if it turns out Sub-slicing won't work without it.
• Changed the way the yamls are concatenated in kueue_manager.

Testing / Documentation

• [ y ] Tests pass
• [ n/a ] Appropriate changes to documentation are included in the PR