I just had the same thing happen to me a few weeks ago during a cross-state bike tour. After I put a boot on the inside of the tire I repaired the cut with a drop of super-glue. I then rode an additional 450 miles on the tire.

When the tire is deflated put a drop into the cut. Then push it together. After the glue sets inflate the tire. My friends who run tubless tires on their mountain bikes tell me that is the standard procedure for puncture repaire on tubless.

Also, like the others have said here, it's safer to put the repaired tire on the back.

Good Luck!