[stable-2.7] Add test constraint for setuptools. (#66426)

* Add test constraint for setuptools.

* Update pip test to work on centos6 container..
(cherry picked from commit 51e5b71)

Co-authored-by: Matt Clay <matt@mystile.com>

changelogs/fragments/ansible-test-setuptools-constraint.yml

@@ -0,0 +1,2 @@
+bugfixes:
+    - ansible-test no longer tries to install ``setuptools`` 45+ on Python 2.x since those versions are unsupported

test/integration/targets/pip/tasks/pip.yml

@@ -510,7 +510,11 @@
 
   - name: install distribute in the virtualenv
     pip:
-      name: distribute
+      # using -c for constraints is not supported as long as tests are executed using the centos6 container
+      # since the pip version in the venv is not upgraded and is too old (6.0.8)
+      name:
+        - distribute
+        - setuptools<45  # setuptools 45 and later require python 3.5 or later
       virtualenv: "{{ output_dir }}/pipenv"
       state: present
 

test/runner/requirements/constraints.txt

@@ -28,3 +28,4 @@ virtualenv < 16.0.0 ; python_version < '2.7' # virtualenv 16.0.0 and later requi
 pyopenssl < 18.0.0 ; python_version < '2.7' # pyOpenSSL 18.0.0 and later require python 2.7 or later
 pyfmg == 0.6.1 # newer versions do not pass current unit tests
 pycparser < 2.19 ; python_version < '2.7' # pycparser 2.19 and later require python 2.7 or later
+setuptools < 45 ; python_version <= '2.7' # setuptools 45 and later require python 3.5 or later