www/kf5-kjs: unbreak after 020693c1

-- Could NOT find Perl (missing: PERL_EXECUTABLE)
[...]
-- The following REQUIRED packages have not been found:

 * Perl, <http://www.perl.org>
   Needed for building kdelibs

CMake Error at /usr/local/share/cmake/Modules/FeatureSummary.cmake:464 (message):
  feature_summary() Error: REQUIRED package(s) are missing, aborting CMake
  run.
Call Stack (most recent call first):
  CMakeLists.txt:88 (feature_summary)

PR:		266007