The loops should continue iterating if the timeout is non-zero and we're
still waiting for the updated value. Otherwise, if things break, we'll
be waiting until we receive a value that never arrives.
Those tests require Python, gobject-introspection and python-dbusmock
making them unsuitable to be run within the uninstalled test suite.
There are no restrictions of dependencies when it comes to installed
tests so use those to exercise GMemoryMonitor.
