{CI} Auto manage milestone

[wangzelin007]

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This checklist is used to make sure that common guidelines for a pull request are followed.

• Auto choose milestone for issue or pull request
• If the current milestone time is more than expected days (7 days), auto set in current milestone.
• If the current milestone time is less than expected days (7 days):
  1. If next milestone exist, auto set in next milestone and reminder user.
  2. If next milestone not exist, auto set in current milestone and reminder user.

Related command

General Guidelines

• Have you run azdev style <YOUR_EXT> locally? (pip install azdev required)
• Have you run python scripts/ci/test_index.py -q locally?

For new extensions:

• My extension description/summary conforms to the Extension Summary Guidelines.

About Extension Publish

There is a pipeline to automatically build, upload and publish extension wheels.
Once your pull request is merged into main branch, a new pull request will be created to update src/index.json automatically.
You only need to update the version information in file setup.py and historical information in file HISTORY.rst in your PR but do not modify src/index.json.

[yonzhan]

CI