Update src/escpos/printer/network.py

Add return type

Co-authored-by: Patrick Kanzler <4189642+patkan@users.noreply.github.com>

src/escpos/printer/network.py

@@ -118,7 +118,7 @@ class Network(Escpos):
         """Read data from the TCP socket."""
         return self.device.recv(16)
 
-    def close(self):
+    def close(self) -> None:
         """Close TCP connection."""
         if not self._device:
             return