docs: Fix configuration with gtk_doc=true and installed_tests=false
Skip the gdbus-object-manager-example which is generated as part of testing.
Program xsltproc found: YES (/usr/bin/xsltproc)
Run-time dependency gtk-doc found: YES 1.32
docs/reference/gio/gdbus-object-manager-example/meson.build:1:0: ERROR:
Unknown variable "libgdbus_example_objectmanager_dep".
Seen with master @ 2b741aaf and 2.64.1.
Perhaps there is a better fix but hopefully this illustrates the problem.
Edited by Chris Mayo