Merge #4787

4787: Add index exists function in index_scheduler which stops opening indexes to only check if they exist. r=Kerollmops a=Karribalu

# Pull Request

## Related issue
Fixes #4784

## What does this PR do?
- Added index_exists function in the index_scheduler.
- Resolved opening indexes to only check if they exist.
- Made changes to existing tests to test this function.

## PR checklist
Please check if your PR fulfills the following requirements:
- [x] Does this PR fix an existing issue, or have you listed the changes applied in the PR description (and why they are needed)?
- [x] Have you read the contributing guidelines?
- [x] Have you made sure that the title is accurate and descriptive of the changes?

Thank you so much for contributing to Meilisearch!


Co-authored-by: karribalu <karri.balu123456@gmail.com>

meilisearch/src/analytics/mod.rs

@@ -102,7 +102,7 @@ pub trait Analytics: Sync + Send {
     /// This method should be called to aggregate post facet values searches
     fn post_facet_search(&self, aggregate: FacetSearchAggregator);
 
-    // this method should be called to aggregate a add documents request
+    // this method should be called to aggregate an add documents request
     fn add_documents(
         &self,
         documents_query: &UpdateDocumentsQuery,