Fix Socket#tty? to false on Windows (#13175)

spec/std/socket/socket_spec.cr

@@ -19,6 +19,12 @@ describe Socket, tags: "network" do
     end
   end
 
+  describe "#tty?" do
+    it "with non TTY" do
+      Socket.new(Socket::Family::INET, Socket::Type::STREAM, Socket::Protocol::TCP).tty?.should be_false
+    end
+  end
+
   pending_win32 ".accept" do
     client_done = Channel(Nil).new
     server = Socket.new(Socket::Family::INET, Socket::Type::STREAM, Socket::Protocol::TCP)

src/crystal/system/win32/socket.cr

@@ -335,7 +335,7 @@ module Crystal::System::Socket
   end
 
   private def system_tty?
-    LibC.isatty(fd) == 1
+    false
   end
 
   private def unbuffered_read(slice : Bytes)