Elecrows: Delete problematic variant.cpp

Not needed after USE_ETHERNET_DEFAULT

variants/esp32s3/ELECROW-ThinkNode-G3/variant.cpp

@@ -1,6 +0,0 @@
-#include "NodeDB.h"
-
-void variantDefaultConfig()
-{
-    config.network.eth_enabled = true;
-}

variants/esp32s3/ELECROW-ThinkNode-M7/variant.cpp

@@ -1,6 +0,0 @@
-#include "NodeDB.h"
-
-void variantDefaultConfig()
-{
-    config.network.eth_enabled = true;
-}