docs: don't build plugins doc cache by default

gstreamer/gst-docs#36
17 jobs for docs-do-not-build-plugins-doc-cache-by-default in 55 minutes and 45 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Preparation
passed #304835
gst indent

00:00:32

passed #304834
manifest

00:00:41

 
  Build
passed #304836
build fedora x86_64

00:06:46

passed #304837
build nodebug fedora x86_64

00:06:41

 
  Test
passed #304838
check fedora

00:03:58

passed #304839
integration testsuites fedora

00:11:51

 
  Full Builds
passed #304841
build cerbero android universal

00:12:35

passed #304842
build cerbero cross win32

00:07:07

passed #304843
build cerbero cross win64

00:05:07

passed #304840
build cerbero fedora x86_64

00:07:22

 
  Full Tests
passed #304847
valgrind bad

00:05:48

passed #304844
valgrind base

00:07:25

passed #304848
valgrind ges

00:05:19

passed #304845
valgrind good

00:08:36

passed #304846
valgrind ugly

00:02:20

 
  Apps
passed #304849
android universal examples

00:09:01

 
  Deploy
passed #304850
documentation

00:03:28