Port nRF54L15 to the s145 SoftDevice Arduino core (#11842)

* Remove the Zephyr based nRF54L15 port

* Add nRF54L15 port on the s145 Arduino core: nrf54l15dk and xiao_nrf54l15 variants

* nRF54L: errno-style nrfx results, flush console before assert reset

* nRF54L: log the SoftDevice status on Bluefruit failure, ignore the seed request event

* Support the Wio-LR2021 LoRa Plus expansion board with OLED and K1 on the XIAO nRF54L15 variant

* Consume the nRF54L15 platform, core and bootloader from their repositories

* Pin the nRF54L15 platform to v0.2.0

* nRF52: forward SoftDevice flash events taken by the main loop to the flash driver, log the pairing failure status

* Pin the nRF54L15 platform to v0.2.1

* Pin the nRF54L15 platform to v0.3.0

* Split the XIAO nRF54L15 variant into SX1262 and LoRa Plus environments, seed the SoftDevice on request, add the nrf54l15 CI build script

* Pin the nRF54L15 platform to meshtastic/platform-nordicnrf54 v0.3.1

* NRF54: Fix mtjson generation

---------

Co-authored-by: vidplace7 <vidplace7@gmail.com>

src/main.cpp

@@ -76,12 +76,6 @@ NimbleBluetooth *nimbleBluetooth = nullptr;
 NRF52Bluetooth *nrf52Bluetooth = nullptr;
 #endif
 
-#ifdef ARCH_NRF54L15
-void nrf54l15Setup();
-void nrf54l15Loop();
-NRF54L15Bluetooth *nrf54l15Bluetooth = nullptr;
-#endif
-
 #ifdef MESHTASTIC_ENABLE_APPROTECT
 #include "security/APProtect.h"
 #endif
@@ -852,9 +846,6 @@ void setup()
 #ifdef ARCH_NRF52
     nrf52Setup();
 #endif
-#ifdef ARCH_NRF54L15
-    nrf54l15Setup();
-#endif
 
 #ifdef ARCH_RP2040
     rp2040Setup();
@@ -1483,9 +1474,6 @@ void loop()
 #ifdef ARCH_NRF52
     nrf52Loop();
 #endif
-#ifdef ARCH_NRF54L15
-    nrf54l15Loop();
-#endif
 #ifdef ARCH_RP2040
     rp2040Loop();
 #endif