Merge #5316

5316: Fix the dumpless upgrade corruption r=dureuill a=irevoire

# Pull Request

## Related issue
Fixes https://github.com/meilisearch/meilisearch/issues/5280

## What does this PR do?
- Add a test that ensure we write the version in the index-scheduler even if we have a bug while writing the VERSION file
- Do what was described in the issue


Co-authored-by: Tamo <tamo@meilisearch.com>

crates/milli/src/update/new/indexer/mod.rs

@@ -1,5 +1,5 @@
 use std::sync::atomic::AtomicBool;
-use std::sync::RwLock;
+use std::sync::{Once, RwLock};
 use std::thread::{self, Builder};
 
 use big_s::S;
@@ -21,7 +21,6 @@ use crate::progress::Progress;
 use crate::update::GrenadParameters;
 use crate::vector::{ArroyWrapper, EmbeddingConfigs};
 use crate::{FieldsIdsMap, GlobalFieldsIdsMap, Index, InternalError, Result, ThreadPoolNoAbort};
-use std::sync::Once;
 
 pub(crate) mod de;
 pub mod document_changes;

crates/milli/src/update/upgrade/v1_12.rs

@@ -1,11 +1,10 @@
 use heed::RwTxn;
 
+use super::UpgradeIndex;
 use crate::constants::{VERSION_MAJOR, VERSION_MINOR, VERSION_PATCH};
 use crate::progress::Progress;
 use crate::{make_enum_progress, Index, Result};
 
-use super::UpgradeIndex;
-
 #[allow(non_camel_case_types)]
 pub(super) struct V1_12_To_V1_12_3 {}