GeoWebCache 1.28.6

What's Changed

• chore(deps): bump actions/setup-java from 5 to 6 by @dependabot[bot] in #1572
• [Backport 1.28.x] Validate GWC files for Raster Masking by @geoserver-bot in #1595
• Removing the gwc-sqlite module (1.28.x backport) by @aaime in #1599
• Backport cloud-dependencies-bom to 1.28.x by @groldan in #1592

Full Changelog: 1.28.5...1.28.6