Fix local install error

[MooooCat]

Description

In this PR we fixed a bug with local installation of sdgx.

Motivation and Context

In some python versions, using setup.py will cause errors, so we still use pyproject.toml for local installation.

The relevant explanatory text in the readme document has also been updated simultaneously.

How has this been tested?

The local installation has been tested. Since it does not involve functional changes, it will not cause extra problems.

Types of changes

• Maintenance (no change in code, maintain the project's CI, docs, etc.)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[sweep-ai]

Apply Sweep Rules to your PR?

• Apply: All new business logic should have corresponding unit tests in the tests/ directory.
• Apply: Any clearly inefficient or repeated code should be optimized or refactored.