Significantly slower times on SOLR sync on XWiki 17.10.2 compared to XWiki 16.10.16

Steps to reproduce

1. Start XWiki first, wait for the server to initialize, then stop the instance
2. Delete the <permdir>\data\cache\solr\search_9 from the instance's folder
3. Start XWiki again and access the instance on the browser
4. Right after the log:

   2026-01-20 13:13:33,658 [solr/indexer job group daemon thread - org.xwiki.search.solr.internal.job.IndexerJob@5846f54a([solr, indexer])] INFO  o.x.s.s.i.j.IndexerJob         - Finished job of type [solr.indexer] with identifier [[solr, indexer]]

   open <permdir>\data\jobs\solr\indexer\status.xml

1. Read the last “elapsedTime” value from </progress> section
2. Start XWiki again, this time without deleting anything from the data\cache\solr folder
3. After the same log from Step 4, read the last “elapsedTime” value from </progress> section as well

Expected results

The elapsed time for SOLR sync is short, e.g. on XWiki 16.10.16:

• SOLR sync when index is empty - on XWiki 16.10.16: 1.51 sec
• SOLR sync when there is nothing to do - on XWiki 16.10.16: 502 ms

Actual results

On XWiki 17.10.2, the times are significantly higher:

• SOLR sync when index is empty: 30.96 sec
• SOLR sync when there is nothing to do: 860 ms

Please see more details in the Performance tests report here: https://test.xwiki.org/xwiki/bin/view/Performances/Jetty%20HSQLDB%20single%20wiki%20161016%20to%2017102]