The question you should be asking yourself is not how to "circumvent" the restriction of Strict but why you want to use XHTML Strict 1.0 in the first place?!
In your case I would simple use Transitional as the DTD. Unless of course you are developing for a specific operating system that for instance doesn't allow multiple windows to be opened for instance in a car systems, an IOT, or more exotic appliances. Which is btw the reason why target is absent in the HTML Strict. Strict being deliberately restrictive.
But as you seem to develop for "normal" use, your doc type should reflect that and you should be using:
<!DOCTYPE html> also see why was target removed from xhtml cheers J