nettest: skip known failure mode of TestTestConn/TCP/RacyRead on windows/arm64

For golang/go#52893.

Change-Id: Icb8ec3512608ec7f7fcdafc62161bc836c84605b
Reviewed-on: https://go-review.googlesource.com/c/net/+/412137
Run-TryBot: Bryan Mills <bcmills@google.com>
Auto-Submit: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
diff --git a/nettest/conntest.go b/nettest/conntest.go
index 55ad42a..615f498 100644
--- a/nettest/conntest.go
+++ b/nettest/conntest.go
@@ -398,7 +398,11 @@
 	t.Helper()
 	if nerr, ok := err.(net.Error); ok {
 		if !nerr.Timeout() {
-			t.Errorf("got error: %v, want err.Timeout() = true", nerr)
+			if runtime.GOOS == "windows" && runtime.GOARCH == "arm64" && t.Name() == "TestTestConn/TCP/RacyRead" {
+				t.Logf("ignoring known failure mode on windows/arm64; see https://go.dev/issue/52893")
+			} else {
+				t.Errorf("got error: %v, want err.Timeout() = true", nerr)
+			}
 		}
 	} else {
 		t.Errorf("got %T: %v, want net.Error", err, err)