fix(cocotbext - eth monitors): pass bytes instead of list[int] to callbacks

The drivers are using bytes object for sending packet:
unify for better "loopback" usage.

Author: martinspinler

python/cocotbext/cocotbext/ofm/avst_eth/monitors.py

@@ -37,5 +37,5 @@ async def _monitor_recv(self):
                 packet += data
 
                 if self.bus.eop.value:
-                    self._recv(packet)
+                    self._recv(bytes(packet))
                     packet = None

python/cocotbext/cocotbext/ofm/lbus/monitors.py

@@ -36,5 +36,5 @@ async def _monitor_recv(self):
                     packet += data
 
                     if self.bus.eop.value.integer & (1 << i):
-                        self._recv(packet)
+                        self._recv(bytes(packet))
                         packet = None