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/cases/020_kernel/200_namespace/common.yml

@@ -4,6 +4,3 @@ kernel:
 init:
   - linuxkit/init:78fb57c7da07c4e43c3a37b27755581da087a3b6
   - linuxkit/runc:bf1e0c61fb4678d6428d0aabbd80db5ea24e4d4d
-trust:
-  org:
-    - linuxkit