Remove unecessary playbook

We should be able to set the tox work dir in the job definition.

Also, updates the files matcher so changes to the jobs cause them
to run.

Change-Id: I519a5257bb3806169ee78dee9ac6ae92d282a889

.zuul.d/cross-jobs.yaml

@@ -12,8 +12,11 @@
       .. zuul:jobvar:: tox_envlist
 
          Use the specified tox environments (``ALL`` selects all).
-    run: playbooks/requirements-cross-test
-    files: ^upper-constraints.txt$
+    vars:
+      zuul_work_dir: "{{ (zuul.projects | selectattr('required') | selectattr('name', 'match', '^(?!openstack/requirements)') | list)[0].src_dir }}"
+    files:
+      - upper-constraints.txt
+      - .zuul.d/cross-jobs.yaml
 
 - job:
     name: cross-cinder-py27

playbooks/requirements-cross-test.yaml

@@ -1,5 +0,0 @@
-- hosts: all
-  roles:
-    - role: tox
-      zuul_work_dir: "{{ (zuul.projects | selectattr('required') | selectattr('name', 'match', '^(?!openstack/requirements)') | list)[0].src_dir }}"
-      tox_constraints_file: "{{ ansible_user_dir }}/src/git.openstack.org/openstack/requirements/upper-constraints.txt"