[5.4] Add compat6 behaviour plugin to 5.4 so it is available and enabled when updating to 6.x.#45371

muhme merged 3 commits intojoomla:5.4-devjoomla/joomla-cms:5.4-devfrom

richard67:5.4-dev-add-j6-bc-pluginrichard67/joomla-cms:5.4-dev-add-j6-bc-pluginCopy head branch name to clipboard