Take a decision on devmode for ESP32-H2

[bettio]

According to tests devmode on H2 is not properly working.
There is no wifi, so it crashes when devmode starts.

[petermm]

and presumably same for p4, I suggest a board check here

AtomVM/libs/esp32devmode/src/esp32devmode.erl

Line 85 in c7e0943

maybe_start_network() ->

for those two boards, along with a nice log message.

[UncleGrumpy]

Good point about the P4. I hope to work on Ethernet support soon, so P4 could still use devmode eventually.