HardFault when calling nicla::begin in Platformio.

https://github.com/arduino/ArduinoCore-mbed/blob/838c70238aaee11c7a8a32cf570de4f51ce240f7/libraries/Nicla_System/src/Nicla_System.cpp#L25-L35

Good morning.

I have tried uploading the nicla-blink code using the Platformio IDE. With the Arduino IDE, the code works fine. However, with Platformio, I get a hard fault from the mbed OS:

```
++ MbedOS Fault Handler ++

FaultType: HardFault

Context:
R 0: 00000000
R 1: 2000345C
R 2: 00000001
R 3: 20000BF5
R 4: 00002000
R 5: 00000000
R 6: 20000BEC
R 7: 00000000
R 8: 00000000
R 9: 00000000
R 10: 00000000
R 11: 00000000
R 12: 00016E79
SP : 20003408
LR : 00010753
PC : 00010764
xPSR : 41000000
PSP : 200033E8
MSP : 2000FFC0
CPUID: 410FC241
HFSR : 40000000
MMFSR: 00000000
BFSR : 00000000
UFSR : 00000001
DFSR : 00000000
AFSR : 00000000
Mode : Thread
Priv : Privileged
Stack: PSP

-- MbedOS Fault Handler --

++ MbedOS Error Info ++
Error Status: 0x80FF013D Code: 317 Module: 255
Error Message: Fault exception
Location: 0x10764
Error Value: 0x200087B4
Current Thread: main Id: 0x2000345C Entry: 0x17EE3 StackSize: 0xC00 StackMem: 0x20002838 SP: 0x20003408
For more info, visit: https://mbed.com/s/error?error=0x80FF013D&tgt=NICLA
-- MbedOS Error Info --
```
Using the debugger, the fault is triggered by the `th.start(&nicla::pingI2CThd);` call inside the `nicla::begin()` function. The code used is the following one:

```
#include "Nicla_System.h"

void setup() {
Serial.begin(115200);
while(!Serial);

nicla::begin();
nicla::leds.begin();
}

void loop() {
nicla::leds.setColor(green);
delay(1000);
nicla::leds.setColor(off);
delay(1000);
}
```
The platformio.ini file is the following one:
```
[env:nicla_sense_me]
platform = nordicnrf52
board = nicla_sense_me
framework = arduino
monitor_speed=115200
debug_tool = cmsis-dap
upload_protocol = cmsis-dap
```
I have previously posted the issue in the Platformio community and they have told me that I should post it here(https://community.platformio.org/t/arduino-mbed-thread-issue-on-arduino-nicla/24915).

Thank you for your attention.

Start by comparing the Arduino IDE and PlatformIO builds using the supplied platformio.ini, then inspect Nicla_System.cpp lines 25-35 around nicla::begin() and the th.start call. Reproduce the fault with the provided sketch and debugger; done means nicla::begin() no longer hard-faults under PlatformIO and the blink example runs.

Written by the indexing model from the issue text.