feat(ci): Add changelog workflow

[hoangdv2429]

PR Standards

Opening a pull request should be able to meet the following requirements

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This PR add auto changelog workflow as the following:

When new commit pushed/PR merged to main branch then

Check if a changelog PR already opened:

• (Yes) merge from main branch (with ort strag) if needed, then new changelog entry will be append to changelog.md and update to already open PR then exit.
• (No) checkout from main branch, generate changelog entry and create PR.

Branch should delete automatically on next ci run, or you can delete it manully.

NOTE

Do not create branch "auto-changelog-update-do-not-create-manually" manually.

For Author:

• [ ] Targeted PR against correct branch
• [ ] included the correct type prefix in the PR title
• [ ] Linked to Github issue with discussion and accepted design
• [ ] Targets only one github issue
• [ ] Wrote unit and integration tests
• [ ] All CI checks have passed
• [ ] Added relevant godoc comments

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For Reviewer:

• [ ] confirmed the correct type prefix in the PR title
• [ ] Reviewers assigned
• [ ] confirmed all author checklist items have been addressed

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After reviewer approval:

• [ ] In case targets main branch, PR should be squashed and merged.
• [ ] In case PR targets a release branch, PR should be rebased.