cmake: move up checking DBUS_ENABLE_EMBEDDED_TESTS from subdir test/name-test to test

The whole file is only added with the mentioned variable
set, so it can also be skipped completly one level up.
11 jobs for cmake-fixup in 9 minutes and 18 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Build
passed #4649713
build:cmake

00:04:16

passed #4649710
build:debug

00:09:06

manual #4649715
allowed to fail manual
build:i686-w64-mingw32-cmake
passed #4649714
build:i686-w64-mingw32-debug

00:05:23

manual #4649712
allowed to fail manual
build:legacy
passed #4649709
build:production

00:06:03

manual #4649711
allowed to fail manual
build:reduced
manual #4649718
allowed to fail manual
build:stretch
passed #4649716
build:x86_64-w64-mingw32

00:04:24

passed #4649717
build:x86_64-w64-mingw32-cmake-debug

00:08:37

manual #4649719
allowed to fail manual
build:xenial