Qt6: Update to version 6.7.1 * qt6-qtbase.mk: Update version and checksum. Remove no longer recognized configure switch. * qt6-qtbase-1-fixes.patch: Adjust patch for reorganized CMake files. Remove hunk that is no longer needed. * qt6-qtbase-2-6.7.0-opengl-header.patch: Add new patch. * dist-files.mk: Add new file to list. * qt6-qt5compat.mk, qt6-qtimageformats.mk, qt6-qtsvg.mk, qt6-qttools.mk, qt6-qttranslations.mk: Update checksum.