BLE fixes; magtag name fix

[dhalbert]

• Characteristic and descriptor max_lengths can be zero. Fixes BLE HID Keyboard not working in CircuitPython 6.0 #3746.

• Assure that start_scan() timeout is either zero or >= interval. This is a guess for this fix, but it coincides with working values reported in Low timeout values for BLERadio().start_scan() can lead to safe mode when calling BLERadio().connect() #3826. Fixes Low timeout values for BLERadio().start_scan() can lead to safe mode when calling BLERadio().connect() #3826.

• Assure that start_scan() max timeout is not too large for a uint16_t when passed to nRF SD. Fixes _bleio.Adapter.start_scan does not validate max timeout size #3340.

• Fixes small advertising interval values. Fix check and make sure it's at least 0.02001, to allow for rounding issues, as discussed in start_advertising interval does not accept the minimum 20ms value and may not range check correctly #2930. Fixes start_advertising interval does not accept the minimum 20ms value and may not range check correctly #2930.

• Change MagTag board name to "Adafruit MagTag", so it appears in the support matrix in the right place. Fixes Change "MagTag" to "Adafruit MagTag" in the support matrix #3831.

Tested HID, and tested advertising scans with and without a timeout.

[dhalbert]

The failing build is just a network problem.

[tannewt]

These all look good to me! I think we should merge them into 6.0.x though so we can do a 6.0.1 release.

[dhalbert]

BLE changes applied against 6.0.x instead in #3861. Closing this in favor of that PR. Will merge 6.0.x changes into main afterwards.