Exclude temporary indexes from reindexing

What does this MR do?

Based on suggestion by @iroussos in !43834 (comment 421285620): This excludes any temporary indexes from reindexing.

The reindexing process may fail and leave behind temporary indexes. We recognize those by a prefix of their name and simply exclude them from further reindexing attempts.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content