fix scheduler queue deadlock

[tphoney]

Commit Checklist

Thank you for creating a pull request! To help us review / merge this can you make sure that your PR adheres as much as possible to the following.

The Basics

• Commit is a single logical unit of work, only use multiple commits if doing different tasks
• Commit does not include commented out code or unneeded files
• rebase of main branch

The Content

• Must include testing for bug or feature
• Must include appropriate documentation changes if it is introducing a new feature or changing existing functionality
• Must pass existing test suites

The Commit Message

• Short meaningful description (ex: remove deprecated steps)
• Uses the imperative, present tense: "change", not "changed" or "changes"
• Includes motivation for the change, and contrasts its implementation with the previous behavior

The Pull Request

• What is the reason for this change
• Example usage of the failure for a bug, or configuration and expected output for a feature
• Steps to test the change

[tphoney]

here