Unify RPS and Concurrent Scheduler Paths

[sjmonson]

Unify the scheduling method used for async and synchronous modes in preparation for multi-turn conversation support. This change with also significantly reduce the number PIDs used by GuideLLM at high concurrency.

Relates to #196

[Copilot]

Pull Request Overview

Unifies the scheduling methods for both async and synchronous modes by removing the synchronous mode and standardizing on the asynchronous approach. This change is made in preparation for multi-turn conversation support and significantly reduces process IDs at high concurrency.

• Removed the separate synchronous scheduling path and unified on the asynchronous approach
• Moved type definitions from scheduler-specific module to a more general request types module
• Updated the scheduling strategy to use a consistent start time across all processes

Reviewed Changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/guidellm/scheduler/worker.py	Removed synchronous process loop, unified on async scheduling with updated parameters
src/guidellm/scheduler/strategy.py	Added start_time field and updated request_times methods to use consistent timing
src/guidellm/scheduler/scheduler.py	Removed sync/async branching logic, updated queue handling and process management
src/guidellm/scheduler/result.py	Moved WorkerProcessRequest and WorkerProcessResult dataclasses from worker module
src/guidellm/scheduler/queues.py	New helper module for queue type imports and MPQueues dataclass
src/guidellm/request/types.py	Formatting update to all list
src/guidellm/request/loader.py	Added type hints to abstract methods
src/guidellm/config.py	Updated max_worker_processes calculation and added scheduler_start_delay setting
src/guidellm/benchmark/benchmarker.py	Updated import path for RequestT and ResponseT types
src/guidellm/benchmark/aggregator.py	Updated import path for RequestT and ResponseT types
src/guidellm/scheduler/init.py	Removed exports that moved to other modules
src/guidellm/request/init.py	Added RequestT and ResponseT to exports

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[jaredoconnell]

Looks good to me.