<!-- Describe what has changed in this PR -->
**What changed?**
When a shard context is stopped, it stores whether or not that was due
to a shard ownership lost (SOL) error.
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**Why?**
Upcoming changes to the shard controller will delay re-acquiring a shard
that recently had an SOL error.
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test? Checked in staging env? -->
**How did you test it?**
Tested locally & ci, and in a staging environment (with other changes).
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change to production? -->
**Potential risks**
None; this change is only used by tests.
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sent to the broader community? (Yes/No) -->
**Is hotfix candidate?**
No.