Drop references to system-required template

Our Zuul configuration examples no longer need to mention the
system-required template since we apply it globally using a regular
expression match on project names.

Change-Id: I302d9e8708249a50704d6ffe317b2df653c8e618

doc/source/creators.rst

@@ -1147,7 +1147,6 @@ including the following changes:
       - project:
           name: openstack/<projectname>
           templates:
-            - system-required
             - translation-jobs
 
 

doc/source/drivers.rst

@@ -360,17 +360,13 @@ projects list or add your project to the list if it does not
 exist. You should end up with something like::
 
   - name: openstack/<projectname>
-    templates:
-      - system-required
     check:
       - gate-new-<projectname>-job
     gate:
       - gate-new-<projectname>-job
 
-The template section applies the common ``system-required`` jobs to the
-project (every project should use this template). Then we have
-``gate-new-<projectname>-job`` listed in the check and gate
-pipelines. This says if an event comes in for
+The ``gate-new-<projectname>-job`` listed in the check and gate
+pipelines says if an event comes in for
 ``openstack/<projectname>`` that matches the check or gate pipeline
 triggers run the ``gate-new-<projectname>-job`` job against
 ``openstack/<projectname>`` in the matching pipeline.
@@ -453,7 +449,6 @@ change it to look like this::
   - project:
     name: openstack/<projectname>
     templates:
-      - system-required
       - noop-jobs
 
 Also, remove any jobs and templates you have defined. These can be