Release 2.7.2

Changelog

Core:

• Allow starting / stopping system timers to improve power efficiency

New shield supported:

• Full support for Portenta Cat. M1/NB IoT GNSS Shield via GSM and GPS libraries

RP2040:

• Fix delay()
• Fix binary size calculation
• Match Pico default pins with official pinout #393 (thanks @TedPap )

Patches generated from https://github.com/arduino/mbed-os/tree/extrapatches-6.15.1 (over mbed-os 6.15.1)