Increment version for ai releases

[azure-sdk]

Increment package version after release of azure-ai-agents

[Copilot]

Pull Request Overview

This PR increments the package version to 1.0.0b4 following the release of azure-ai-agents.

• Updated the version constant in _version.py
• Added a new unreleased section in the CHANGELOG for version 1.0.0b4

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
sdk/ai/azure-ai-agents/azure/ai/agents/_version.py	Updated version string from "1.0.0b3" to "1.0.0b4".
sdk/ai/azure-ai-agents/CHANGELOG.md	Added an unreleased section for version 1.0.0b4 with placeholders for changes.

[github-actions]

Hi @azure-sdk. Thank you for your interest in helping to improve the Azure SDK experience and for your contribution. We've noticed that there hasn't been recent engagement on this pull request. If this is still an active work stream, please let us know by pushing some changes or leaving a comment. Otherwise, we'll close this out in 7 days.

[github-actions]

Hi @azure-sdk. Thank you for your contribution. Since there hasn't been recent engagement, we're going to close this out. Feel free to respond with a comment containing /reopen if you'd like to continue working on these changes. Please be sure to use the command to reopen or remove the no-recent-activity label; otherwise, this is likely to be closed again with the next cleanup pass.