Remove unused RX boosted gain mode functions and related preprocessor directives across multiple variants

src/helpers/radiolib/RadioLibWrappers.h

@@ -54,6 +54,9 @@ public:
   virtual float getLastSNR() const override;
 
   float packetScore(float snr, int packet_len) override { return packetScoreInt(snr, 10, packet_len); }  // assume sf=10
+
+  virtual void setRxBoostedGainMode(bool) { }
+  virtual bool getRxBoostedGainMode() const { return false; }
 };
 
 /**