6.1.0 Backported Issues

- Remove guava dependency from indexer-core #null
- Add ability to set the temporary index directory for index update #null
- Fix an InputStream leak in indexer-reader Utils #null
- switch from Git-WIP to Gitbox #null
- Remove TrueZip dependency #null
- Upgrade parent to 31 #null
- Add getName() to Record.EntryKey #null
- Move to Java 8 as minimum Java version #null
- Remove usages of pre-Lucene 4.0 deprecated code #null
- Fix CLI shading #null
- Remove deprecated usages of BooleanQuery constructor - use Builder instead #null
- Maven repository indexing error: java.nio.channels.OverlappingFileLockException #null
- Reset the correct stream in IndexDataReader #null
- Migrate the indexer to Lucene 8.x #null
- Excluding additional dependencies from shaded jar #null
- Upgrade maven-parent to version 34 #null
- use Files.createTempDirectory(...) instead of custom code around File.createTempFile(...) #null
- Update dependencies (except Lucene) #null
- Extend JarFileContentsIndexCreator to support zip files #null
- Upgrade mave-surefire/failsafe-plugin 2.21.0 #null
- Shared GitHub Actions #null

This is a release-tracking issue containing many backported changes, but it names no files, tests, or linked issues; the entries are the only starting point. Review each listed change in its corresponding project history and determine which remain unfinished. Done means all listed 6.1.0 backports are completed and the release scope is closed.

Written by the indexing model from the issue text.