Release v8.7.0

[rgbkrk]

Given all the changes since the last release (v8.6.3), let's work towards publishing v8.7.0.

• Kick off release https://github.com/jupyter/jupyter_client/actions/runs/20074351249
• Update the Draft Release
• Publish release https://github.com/jupyter/jupyter_client/actions/runs/20074525107
• Verify PyPI
• Verify release https://github.com/jupyter/jupyter_client/releases/tag/v8.7.0

[rgbkrk]

Ok this is done but the check_release step failed.