The deletion of a subwiki do not trigger the deletion of the solr index

XWiki version: 9.8.1

Steps to reproduce:

• On the main wiki go the the 'Wiki index' page and create a sub wiki named 'test' with default options.
• On the subwiki 'test' create a page named 'Sandbox.SolrTest'
• On the subwiki 'test' go to the xwiki search and search for 'SolrTest', the page 'Sandbox.SolrTest' should be returned as a result.
• On the main wiki go to the 'Wiki index' page and delete the 'test' subwiki
• On the main wiki go the 'Wiki index' and re-create the 'test' subwiki
• Once the 'test' subwiki is created go to the xwiki search and search for 'SolrTest'.

Expected result: Nothing is returned by the solr search
Actual result: a result is returned for the page 'Sandbox.SolrTest' ... it means that the page is still in the solr index.