Do not use gitlab-ci cache and ccache for CI.

4 jobs for <span class="ref-name">fix/do-not-use-gitlab-ci-cache</span> in 25 minutes and 58 seconds (queued for 49 seconds)
Status Job ID Name Coverage
  Test
passed #6464
docker
job-debian9-ninja-clang

00:06:12

passed #6463
docker
job-debian9-ninja-gcc

00:07:42

passed #6465
macosx
job-macosx-ninja

00:08:14

passed #6466
windows
job-windows-vs2015

00:11:48