docs: update Flux2-dev quick start guide for Ascend A3.

[wang-shuibin]

Description

update Flux2-dev quick start guide for Ascend A3.

Related Issues

docs: update Flux2-dev quick start guide for Ascend A3.

Change Type

• Bug fix
• New feature
• Performance improvement
• Refactor
• Documentation
• Test
• Build or CI

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Reviewer Notes