Solr re-indexes many documents after restarting on PostgreSQL

Steps to reproduce:

1. Create an XWiki instance with PostgreSQL, e.g., following the setup instructions for Docker at https://github.com/xwiki/xwiki-docker?tab=readme-ov-file#for-postgresql-on-tomcat
2. Create some content and wait for indexing to complete.
3. Restart the wiki and look at the log.

Expected result:

During startup, no pages are re-indexed and thus a log line like INFO o.x.s.s.i.j.IndexerJob - 0 documents added, 0 deleted and 0 updated during the synchronization of the Solr index. is logged shortly after startup.

Actual result:

Many documents are re-indexed and the log line is more like INFO o.x.s.s.i.j.IndexerJob - 1023 documents added, 1023 deleted and 0 updated during the synchronization of the Solr index.

Upon closer investigation, this seems to be an ordering difference between PostgreSQL and Solr: In Solr, AI.Code.CKEditorPlugin is before AI.Code.ChatOriginConfig while in PostgreSQL, AI.Code.ChatOriginConfig is first. This seems to be about case sensitivity.