Dev Task: Reindex model_run_predictions

**Describe the task**
model_run_predictions is reindexed so the space of the existing index is reduced

**Acceptance Criteria**
- [ ] Space of model_run_predictions indexes are much less than 12GB

**Additional context**
- Migration? Job?

No file, test, or entry point is named. Start by locating model_run_predictions and measuring the current index sizes, then determine whether a migration or job is appropriate; done means the indexes occupy much less than 12GB.

Written by the indexing model from the issue text.