validate:launcher: Do not take CK_DEFAULT_TIMEOUT into account to set the timeout

The timeout is what is set in the meson build definition otherwise we will not behave as 'meson test' which we should avoid
4 jobs for check_timeout in 6 minutes and 57 seconds
Status Job ID Name Coverage
  Preparation
passed #58327
gst indent

00:00:22

passed #58326
manifest

00:00:24

 
  Build
passed #58328
build fedora x86_64

00:03:06

 
  Full Builds
passed #58329
build android arm64 api28

00:03:26