mongodb/mongo-c-driver@f2c1bb7 introduced the following change to libbson's JSON output:

Previously, empty arrays and documents would serialize with either one or two spaces depending on whether it is nested. Empty arrays and documents now consistently serialize with just one space.

This broke several tests in the libmongoc latest Evergreen task.

We should address this with a %w EXPECTF pattern, which can later be removed once the libmongoc dependency is formally bumped to 1.30.