runtime: disable TestCrashDumpsAllThreads on openbsd/mips64

This test fails consistently on openbsd/mips64 - disable it until we can investigate
and resolve the issue.

Updates #42464

Change-Id: Ie640f776823137a967a12817ff18953207f558a4
Reviewed-on: https://go-review.googlesource.com/c/go/+/268438
Trust: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
diff --git a/src/runtime/crash_unix_test.go b/src/runtime/crash_unix_test.go
index fc87f37..6c42cb9 100644
--- a/src/runtime/crash_unix_test.go
+++ b/src/runtime/crash_unix_test.go
@@ -70,6 +70,10 @@
 		t.Skipf("skipping; not supported on %v", runtime.GOOS)
 	}
 
+	if runtime.GOOS == "openbsd" && runtime.GOARCH == "mips64" {
+		t.Skipf("skipping; test fails on %s/%s - see issue #42464", runtime.GOOS, runtime.GOARCH)
+	}
+
 	if runtime.Sigisblocked(int(syscall.SIGQUIT)) {
 		t.Skip("skipping; SIGQUIT is blocked, see golang.org/issue/19196")
 	}