This fixes up a load of '[un]expected return statement' errors in the
tests. Mostly property getters which I've filled in with `pulumi.get`
but some of the tests were explictly checking things worked when the
getter was an empty method body.
A regression was introduced in Python 3.11.9 and 3.12.3 that breaks lazy
loaded `config` modules in generated Pulumi provider Python SDKs. It's
unclear if this is going to be addressed in subsequent patch releases of
Python, so we workaround the problem by using a copy of the Python
stdlib's `_LazyModule` and `LazyLoader` classes that don't have the
regression, as suggested by the Python maintainers.
Fixes#15882
Test code should be formatted and linted the same as library code. This
is the first step of that, simply including ./lib/test to the folder
that the black formatter runs on.