Add support for changing buildroot versions

exploitdb/ctfsetup/qemu/buildroot_compile.sh

exploitdb/ctfsetup/qemu/buildroot_menuconfig.py

exploitdb/ctfsetup/qemu/buildroot_prepare.sh

exploitdb/ctfsetup/qemu/buildroot_setup.py

exploitdb/ctfsetup/qemu/buildroot_utils.py

exploitdb/ctfsetup/qemu/lib/kconfiglib.py

exploitdb/ctfsetup/qemu/settings.py

exploitdb/ctfsetup/qemu/setup.py

exploitdb/ctfsetup/qemu/setup_dependencies.sh

exploitdb/ctfsetup/qemu/utils.py