drop validation from CI, it does not work reliably enough

1 job for master in 3 minutes and 5 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
failed #6326
fp-timing
build-iris.dev

00:03:05

 
Name Stage Failure
failed
build-iris.dev Test There is an unknown failure, please try again
make[1]: *** [all] Error 2
make[1]: Leaving directory '/builds/FP/iris-examples'
Makefile:6: recipe for target 'all' failed
make: *** [all] Error 2

real 0m20.746s
user 0m23.200s
sys 0m1.130s
ERROR: Job failed: exit code 1