Add xiaomi mi smart humidifier 2 to the unsupported list

[TimTProd]

Basically the model mjjsq05dy has a proprietary Xiaomi chip MHCWB4P-B.

[TimTProd]

Well I did manage to flash it without swapping like in #83 and #84. Here is my process: https://github.com/TimTProd/esphome-mi-smart-humidifier-2/. I believe that this can work with some other wifi modules as well.

[haydenmc]

Woah, great work! If I'd known this was possible I wouldn't have swapped out the module! Thank you!!

[LayerCakeMakes]

Very interesting. It seems the MHCWB5G-B I have is based on the Boufallo BL602C which unfortunately is on libretinys unsupported list for now, though someone seems to have flashed some devices with custom firmware so maybe something could be done here too. There is already an issue for libretiny created though it's very low priority.