LoRa-RP2040.cpp: fix packet duplication when using the parsePacket method in a loop.

I found this workaround here:

 sandeepmistry/arduino-LoRa#463 (comment)

Author: tomicooler

src/LoRa-RP2040.cpp

@@ -227,6 +227,7 @@ int LoRaClass::parsePacket(int size)
 
   // clear IRQ's
   writeRegister(REG_IRQ_FLAGS, irqFlags);
+  writeRegister(REG_IRQ_FLAGS, irqFlags);
 
   if ((irqFlags & IRQ_RX_DONE_MASK) && (irqFlags & IRQ_PAYLOAD_CRC_ERROR_MASK) == 0) {
     // received a packet