FindBISON declares output file twice when VERBOSE is specified
I was taking a look at some multiple rules generate XXX
warnings from ninja while investigating https://github.com/michaelforney/samurai/pull/11, and discovered that it was caused by BISON_TARGET
and its verbose output.
The .txt file is listed as an output of a copy action here, and added to the main bison command outputs here. I believe that the latter is incorrect, and simply removing those two lines will fix the issue.