Qt 6.6.0 Feature Freeze: Update 'dev' release description files for next minor (or major) release

Update both lgpl and commercial def confs:

• https://codereview.qt-project.org/gitweb?p=qtsdk/tqtc-qtsdk.git;a=blob;f=packaging_tools/configurations/releases/release-qt6-dev-lgpl.ini;h=3aefe39122613c1bcb8164360b9ffd6ed878a14f;hb=HEAD
• https://codereview.qt-project.org/gitweb?p=qtsdk/tqtc-qtsdk.git;a=blob;f=packaging_tools/configurations/releases/release-qt6-dev.ini;h=77a1702655666e474808bb0df2a1c0f8c84df133;hb=HEAD

At least qt_version, qt_version_minor, qt_pkg_version_minor, qt_sorting_priority & qtcreator_version needs an update