Revert "Update to tip of master in periodic jobs"

This reverts commit 32978fe729.

The update to the project-config code is moved into the dependent
change in base-jobs, alongside the same thing for system-config.
This way the workaround is in one place.

This also expands the notes in the project-config sync role to better
explain what it is doing.

Depends-On:  https://review.opendev.org/c/opendev/base-jobs/+/862853
Change-Id: I492c01159665e7e7c6684ad36d57388e55127861

playbooks/roles/sync-project-config/README.rst

@@ -1 +1,14 @@
 Sync project-config to remote host
+
+This syncs the ``project-config`` repo checked out on the bastion host
+(which is actually running the Ansible that runs this role) to the
+current host.  This repo holds configuration for some production hosts
+and thus we want to make sure to deploy those services with the
+checked-out tree Zuul has prepared for a given deploy-pipeline CD job
+run (i.e. so we apply config updates in commit order).
+
+Also see the `setup-src
+<https://opendev.org/opendev/base-jobs/src/branch/master/playbooks/infra-prod/setup-src.yaml>`__
+to see where this checkout is setup; there are some tricks -- for
+example for hourly and periodic jobs we want to ensure we run from
+master at the time the job runs, not at the time the job was enqueued.

playbooks/roles/sync-project-config/defaults/main.yaml

@@ -1,3 +1,2 @@
 project_config_dest: /opt/project-config
 project_config_subdir: ""
-infra_prod_run_from_master: "{{ zuul.pipeline|default('') in ['periodic', 'opendev-prod-hourly'] }}"

playbooks/roles/sync-project-config/tasks/main.yaml

@@ -3,14 +3,6 @@
     path: '{{ project_config_dest }}'
     state: directory
 
-- name: Update from master on bastion host
-  when: infra_prod_run_from_master|bool
-  delegate_to: '{{ groups["bastion"][0] }}'
-  git:
-    repo: https://opendev.org/openstack/project-config
-    dest: '{{ project_config_src }}'
-    force: yes
-
 - name: Sync project-config repo
   synchronize:
     src: '{{ project_config_src }}/{{ project_config_subdir }}'