Update release workflow documentation and remove automated PR creation step

[YunchuWang]

Summary

What changed?

Why is this change needed?

Issues / work items

• Resolves #
• Related #

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Project checklist

• Release notes are not required for the next release
  • Otherwise: Notes added to CHANGELOG.md
• Backport is not required
  • Otherwise: Backport tracked by issue/PR #issue_or_pr
• All required tests have been added/updated (unit tests, E2E tests)
• Breaking change?
  • If yes:
    • Impact:
    • Migration guidance:

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• Yes, AI helped write parts of this PR (e.g., GitHub Copilot)
• Yes, an AI agent generated most of this PR

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Testing

Automated tests

• Result: Passed / Failed (link logs if failed)

Manual validation (only if runtime/behavior changed)

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Notes for reviewers

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[Copilot]

Pull request overview

This pull request updates the release preparation workflow to remove automatic pull request creation, shifting to a manual PR creation process. The workflow previously automated PR creation using GitHub's CLI but now provides a manual link in the workflow summary instead.

Changes:

• Removed automated PR creation step from the Prepare Release workflow
• Removed pull-requests: write permission that is no longer needed
• Updated workflow to output a clickable link in the summary for manual PR creation
• Updated documentation to reflect the new manual PR creation process

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
.github/workflows/prepare-release.yaml	Removed the "Create Pull Request" step (37 lines), removed pull-requests: write permission, and updated workflow summary to provide manual PR creation instructions with a pre-formatted link
doc/release_process.md	Updated documentation to reflect manual PR creation process, replacing the previous automated step with detailed instructions for creating a PR manually after workflow completion

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[Copilot]

The URL format in the documentation is inconsistent with the URL generated by the workflow. The workflow (line 194 in prepare-release.yaml) generates a URL with query parameters that pre-populate the PR title and expand the form: ?expand=1&title=Release+v${NEW_VERSION}. The documentation should match this format for consistency and better user experience, as it will pre-fill the PR title when users click the link.

Suggested change

	1. Go to the workflow run summary and click the **Create PR** link, or navigate to: `https://github.com/microsoft/durabletask-js/compare/main...release/vX.Y.Z`
	1. Go to the workflow run summary and click the **Create PR** link, or navigate to: `https://github.com/microsoft/durabletask-js/compare/main...release/vX.Y.Z?expand=1&title=Release+vX.Y.Z`