nexuscancellation, nexuscontextpropagation, and nexusmultipleargs were
referencing ./src/main/java/io/temporal/samples/nexus/service/description.md
which only exists in the nexus sample directory.

nexuscancellation, nexuscontextpropagation, and nexusmultipleargs
import classes from the base nexus package. The include field tells
the CLI to extract the nexus package alongside the variant.

Required by the nexus ClientOptions class which is included as a
dependency of the nexus variant samples.

…ngClient

TripBookingSaga class does not exist. The sample uses separate worker
and client processes.

The DSL sample loads sampleflow.json from the classpath resources.
Without this include, the resource directory is not extracted.

This reverts commit a920d49.