Add --workers parameter to the dev command

[AliHezarpisheh]

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Example Code

fastapi dev --workers 4

Description

Feature Request: Add --workers Parameter to fastapi dev Command

Problem:
Currently, the fastapi dev command does not accept the --workers parameter. In my development environment, I want to mimic a distributed environment similar to production, but I cannot achieve this with fastapi dev. Instead, I must use fastapi run, which is less ideal for development.

Proposed Solution:
Add support for the --workers parameter to the fastapi dev command. This would allow developers to run multiple workers in their development environment.

Additional Context:
I am open to implementing this feature and submitting a PR if approved by the maintainers.

Operating System

Linux

Operating System Details

Doesn't matter.

Python Version

3

Additional Context

No response