[test] Ignore failures from the remote side closing the socket in test of handling many pending connections.

TEST=standalone/io/many_pending_secure_sockets_test
Bug: #61072
Change-Id: I9ce7130db90c8b04f832a4c4ee7ccdaec97126d0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/439546
Reviewed-by: Brian Quinlan <[email protected]>
Commit-Queue: Ryan Macnak <[email protected]>

Author: rmacnak-google

tests/standalone/io/many_pending_secure_sockets_test.dart

@@ -7,11 +7,18 @@
 import "dart:io";
 
 test(int i) async {
-  var socket = await RawSecureSocket.connect("www.google.com", 443);
-  await Future.delayed(
-    Duration(seconds: 6), // More than the thread pool timeout.
-  );
-  socket.close();
+  try {
+    var socket = await RawSecureSocket.connect("www.google.com", 443);
+    await Future.delayed(
+      Duration(seconds: 6), // More than the thread pool timeout.
+    );
+    socket.close();
+  } catch (e, st) {
+    // Ignore failures from the remote side rejecting/closing the connection.
+    if (!e.toString().contains("Connection reset by peer")) {
+      rethrow;
+    }
+  }
 }
 
 main() async {