Remove nonexistent permission from Licence Finder API user.

This was causing the Signon API to crash when attempting to create the
Authorisation.

Licence Finder doesn't currently have any additional permissions
on its Authorisation for Publishing API. Publishing API doesn't have a
permission called `internal_app` (or anything similar).

https://trello.com/c/F7vSHnws/841

charts/signon-resources/templates/bootstrap-job.yaml

@@ -371,7 +371,7 @@ spec:
                   "username": "licence-finder",
                   "email": "licence-finder@{{ .Values.govukEnvironment }}.{{ .Values.govukDomainExternal }}",
                   "bearer_tokens": [
-                    { "application_slug": "publishing-api-ec2", "permissions": ["internal_app"] }
+                    { "application_slug": "publishing-api-ec2" }
                   ]
                 }
               }