feat(variants): add Waveshare ESP32-S3-LR1121

ESP32-S3FH4R2 (4MB flash, 2MB PSRAM, native USB-CDC) with an LR1121.
Pins, the DIO5/DIO6 RF switch table and the 1.8 V TCXO follow the HF
schematic and Waveshare's examples. Envs: repeater, room server,
companion USB/BLE and KISS modem, all on min_spiffs so roles share one
partition layout.

Only RFO_HP_LF is wired (R4 on RFO_LP_LF is not fitted), so the new
opt-in LR1121_FORCE_HP_PA flag keeps RadioLib on the HP PA at <= 14 dBm,
where it would otherwise select the unconnected LP PA.

variants/waveshare_esp32s3_lr1121/target.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#define RADIOLIB_STATIC_ONLY 1
+#include <RadioLib.h>
+#include <helpers/radiolib/RadioLibWrappers.h>
+#include <helpers/radiolib/CustomLR1121Wrapper.h>
+#include <helpers/AutoDiscoverRTCClock.h>
+#include <helpers/SensorManager.h>
+#include "WaveshareS3LR1121Board.h"
+
+extern WaveshareS3LR1121Board board;
+extern WRAPPER_CLASS radio_driver;
+extern AutoDiscoverRTCClock rtc_clock;
+extern SensorManager sensors;
+
+bool radio_init();
+mesh::LocalIdentity radio_new_identity();