v2.7.0-RC1

What's Changed

• Update README for XOOPS Core version change to 2.7.x by @mambax7 in #2
• Bump actions/checkout from 5.0.0 to 6.0.2 by @dependabot[bot] in #1
• Delete xbootstrap and xswatch4 by @mambax7 in #3
• add xtailwind and xtailwind2 themes by @mambax7 in #4
• chore(tinymce): update TinyMCE 7 from 7.7.2 to 7.9.2 by @mambax7 in #6
• Feature/upgrade 270 by @mambax7 in #5
• add theme screenshots for installation by @mambax7 in #7
• fix(system-menus): create and seed menu tables during fresh install by @mambax7 in #8
• refactor(upgrade): migrate upgrade framework to namespaced classes with DI by @mambax7 in #10

Full Changelog: https://github.com/XOOPS/XoopsCore27/commits/v2.7.0-RC1