encoding/jsonschema: use StrictFeatures in external tests
The spec specifically says that unknown keywords should be ignored, so
use `StrictFeatures` in the external tests so they correspond better to
the spec.
Also, use `StrictFeatures` rather than `Strict` in one of the
constraints, as we should never be using `Strict` as a condition.
Signed-off-by: Roger Peppe <rogpeppe@gmail.com>
Change-Id: If4d66285b6a9f77bb6ae4915a4818967290578f2
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1201117
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Unity-Result: CUE porcuepine <cue.porcuepine@gmail.com>
TryBot-Result: CUEcueckoo <cueckoo@cuelang.org>