Merge ~paride/curtin:vmtest-add-jsonschema-dep into curtin:master

[Paride Legovini]

vmtest: add dependency on python3-jsonschema

python3-jsonschema is needed to perform the schema-validate stage of the
vmtest target. This branch makes vmtest-system-setup install the package
among the other vmtest dependencies.

[Server Team CI bot (server-team-bot)]

PASSED: Continuous integration, rev:40664c6c897e94e7f977d4b77e0c4621f22f1b4b
https://jenkins.ubuntu.com/server/job/curtin-ci/1252/
Executed test runs:
    SUCCESS: https://jenkins.ubuntu.com/server/job/curtin-ci/nodes=metal-arm64/1252
    SUCCESS: https://jenkins.ubuntu.com/server/job/curtin-ci/nodes=metal-ppc64el/1252
    SUCCESS: https://jenkins.ubuntu.com/server/job/curtin-ci/nodes=metal-s390x/1252
    SUCCESS: https://jenkins.ubuntu.com/server/job/curtin-ci/nodes=torkoal/1252

Click here to trigger a rebuild:
https://jenkins.ubuntu.com/server/job/curtin-ci/1252/rebuild

review: Approve (continuous-integration)

[Ryan Harper (raharper)]

review: Approve

diff --git a/tools/vmtest-system-setup b/tools/vmtest-system-setup
index bc790cb..b9185db 100755
--- a/tools/vmtest-system-setup
+++ b/tools/vmtest-system-setup
@@ -16,6 +16,7 @@ DEPS=(
   make
   net-tools
   python3
+  python3-jsonschema
   python3-nose
   python3-simplestreams
   python3-yaml