Remove use-cached-repos role

This is no longer needed after we switch to prepare-workspace-git.

Depends-On: https://review.opendev.org/680703
Change-Id: I3830e4c84c6f8bea465cce22b7e3ae048bf60882

roles/use-cached-repos/README.rst

@@ -1,9 +0,0 @@
-Clone repos from the image cache into the workspace
-
-Clon any repos cached on the remote node (via the image build process)
-that this job uses into the workspace.  If a repo doesn't exist, clone
-it from its source.
-
-These repos are neither up to date, nor do they contain the changes
-that Zuul has prepared.  A separate role should synchronize the local
-and remote repos.

roles/use-cached-repos/tasks/main.yaml

@@ -1,41 +0,0 @@
-- name: Find locally cached git repos
-  stat:
-    path: "/opt/git/{{ item.name }}"
-  with_items: "{{ zuul.projects.values() | list }}"
-  register: cached_repos
-
-- name: Clone cached repo to workspace
-  command: "git clone /opt/git/{{ item.0.name }} {{ ansible_user_dir }}/{{ item.0.src_dir}}"
-  args:
-    creates: "{{ ansible_user_dir }}/{{ item.0.src_dir}}"
-  when: item.1.stat.exists
-  with_together:
-    - "{{ zuul.projects.values() | list }}"
-    - "{{ cached_repos.results }}"
-  # ANSIBLE0006: If we use the git module, we get warning
-  # ANSIBLE0004 since we  do not give an explicit version
-  tags:
-    - skip_ansible_lint
-
-- name: Clone upstream repo to workspace
-  command: "git clone https://{{ item.0.canonical_hostname }}/{{ item.0.name}} {{ ansible_user_dir }}/{{ item.0.src_dir}}"
-  args:
-    creates: "{{ ansible_user_dir }}/{{ item.0.src_dir}}"
-  when: not item.1.stat.exists
-  with_together:
-    - "{{ zuul.projects.values() | list }}"
-    - "{{ cached_repos.results }}"
-  # ANSIBLE0006: If we use the git module, we get warning
-  # ANSIBLE0004 since we  do not give an explicit version
-  tags:
-    - skip_ansible_lint
-
-- name: Remove origin from local git repos
-  # To be idempotent, remove origin only if it's found in the local list.
-  shell: "git remote -v | grep origin && git remote rm origin || true"
-  args:
-    chdir: "{{ ansible_user_dir }}/{{ item.src_dir}}"
-  with_items: "{{ zuul.projects.values() | list }}"
-  # ANSIBLE0006: git remote is not supported by ansible module
-  tags:
-    - skip_ansible_lint