remove ansible_version from the API config and metrics endpoints

AWX no longer includes Ansible on the control plane and there is no
"default" version of Ansible aside from what's configured at the
Execution Environment level

see: https://github.com/ansible/awx/issues/9472

awx/ui_next/src/components/AppContainer/AppContainer.test.jsx

@@ -10,13 +10,11 @@ import AppContainer from './AppContainer';
 jest.mock('../../api');
 
 describe('<AppContainer />', () => {
-  const ansible_version = '111';
   const version = '222';
 
   beforeEach(() => {
     ConfigAPI.read.mockResolvedValue({
       data: {
-        ansible_version,
         version,
       },
     });
@@ -93,7 +91,6 @@ describe('<AppContainer />', () => {
 
     // check about modal content
     const content = await waitForElement(wrapper, aboutModalContent);
-    expect(content.find('dd').text()).toContain(ansible_version);
     expect(content.find('pre').text()).toContain(`<  AWX ${version}  >`);
 
     // close about modal