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>

linuxkit.yml

@@ -36,7 +36,3 @@ services:
 files:
   - path: etc/linuxkit-config
     metadata: yaml
-trust:
-  org:
-    - linuxkit
-    - library