A laser is not just light. It is a specific wavelength. X-Rays are a spectrum. The EUV/soft X-ray is a part of that spectrum. There's also other properties that you want from the laser. But this tape-x-rays won't be easy to control or uniform in wavelength. Making it not a laser, even if you could collimate it.

https://en.wikipedia.org/wiki/Laser

Thanks for this info. I assumed there was a specific reason they used this setup. I was joking about using tape.

Too bad we can't make x-ray leds.

It's easier to generate hard X-rays than EUV. An X-ray tube is just an electron gun and a copper target.