Check if `microcontroller.reset()` in quick succession will enter double-reset safe mode

[dhalbert]

#10899 originally added this doc note in shared-bindings/alarm/SleepMemory.c:

//|     .. note::
//|         Programs that call ``microcontroller.reset()`` should wait at least
//|         one second after boot before resetting, otherwise CircuitPython's
//|         double-reset safe mode detector may activate. See
//|         ``supervisor/shared/safe_mode.c``.

@tannewt wasn't sure this was true. I removed it in #10989. Revisit this later. If it is true, maybe it's a bug.
Tagging @lzrd, who added the comment, for interest.

[grgrant]

I wrote a program to do repeated microcontroller.reset()'s 2 and 4x on OS releases from 1.0.3 to 10.3.0-alpha.2 and I am unable to get it to enter double-reset safe mode. I had no settings.toml or boot.py to ensure quickest possible boot after reset. I tried it on ESP32-S3 Reverse TFT. QtPy ESP32-S3 N4R2 and a Feather ESP32-S2 TFT. Here is my program:

"""
Test to see if two microcontroller.resets without 1 second sleep will trigger safe mode
No boot.py or settings.toml to reduce any WiFi or other early initialization to eat time
"""

from microcontroller import nvm,reset
import time

# Number of times to do a microcontroller reset
RESETS = 4 # Tried 2 also

if nvm[0] < RESETS:
    nvm[0] += 1  # Count of  resets
    print(f"Doing reset #{nvm[0]}")
    reset()
else:
    time.sleep(5) # Make sure we can see this when it happens
    print(f"No reset because {nvm[0]} RESETS reached -- check if in safe mode")
    nvm[0] = 0 # reset for next test