yaml: Remove trust section from examples and tests

With 561ce6f4be ("Remove Notary and Content Trust") we
removed support for content trust. No need to have it
in the YAMLs either.

Signed-off-by: Rolf Neugebauer <rn@rneugeba.io>

test/pkg/ns/template.yml

@@ -16,6 +16,3 @@ onboot:
   - name: poweroff
     image: linuxkit/poweroff:afe4b3ab865afe1e3ed5c88e58f57808f4f5119f
     command: ["/bin/sh", "/poweroff.sh", "3"]
-trust:
-  org:
-    - linuxkit