This reverts commit df304fe674.
This kind of addresses #31. Apparently we can't predict which wpa_supplicant is bundled into the system by inspecting Android version, especially now that it is put into /vendor/bin/hw (see also Project Treble: https://source.android.com/devices/architecture/vndk/).
It might be cool if someone makes a Magisk module that replaces wpa_supplicant to the latest version.