fixup: Name qEcho's unused parameter

This does cause pyright to report the unused parameter though

Author: dsandersllvm

lldb/packages/Python/lldbsuite/test/gdbclientutils.py

@@ -245,7 +245,7 @@ def qProcessInfo(self):
     def qHostInfo(self):
         return "ptrsize:8;endian:little;"
 
-    def qEcho(self, _: int):
+    def qEcho(self, num: int):
         return "E04"
 
     def qQueryGDBServer(self):