[3.11] gh-111347: Remove wrong assertion in test_sendfile (GH-111377) (#111462)

gh-111347: Remove wrong assertion in test_sendfile (GH-111377)

Windows is different.
(cherry picked from commit fa35b9e)

Co-authored-by: zcxsythenew <[email protected]>

Author: miss-islington

Lib/test/test_asyncio/test_sendfile.py

@@ -470,8 +470,11 @@ def test_sendfile_close_peer_in_the_middle_of_receiving(self):
 
         self.assertTrue(1024 <= srv_proto.nbytes < len(self.DATA),
                         srv_proto.nbytes)
-        self.assertTrue(1024 <= self.file.tell() < len(self.DATA),
-                        self.file.tell())
+        if not (sys.platform == 'win32'
+                and isinstance(self.loop, asyncio.ProactorEventLoop)):
+            # On Windows, Proactor uses transmitFile, which does not update tell()
+            self.assertTrue(1024 <= self.file.tell() < len(self.DATA),
+                            self.file.tell())
         self.assertTrue(cli_proto.transport.is_closing())
 
     def test_sendfile_fallback_close_peer_in_the_middle_of_receiving(self):