fix(ci): wait for blocking

[cmgoffena13]

Description

There's a race condition in test_restatement_plan_detects_prod_deployment_during_restatement -- it wants to raise ConflictingPlanError. Restatement happens and while its happening a plan happens and it should error. Sometimes the plan succeeds before the restatement even happens and no error is raised. This fixes that race condition.

Test Plan

Ran controlled test. It happens with multiple workers where resources are shared and timing issues are introduced.

Checklist

• I have run make style and fixed any issues
• I have added tests for my changes (if applicable)
• All existing tests pass (make fast-test)
• My commits are signed off (git commit -s) per the DCO