baremetal: Install Docker SDK less than 5.0.0

Docker 5.0.0 [1] dropped requirement for six, but still imports it.

[1]: https://github.com/docker/docker-py/issues/2807

Closes-Bug: #1928915
Change-Id: I726541f4b3fdc357387a44c6a2153593a10bf282

ansible/roles/baremetal/tasks/install.yml

@@ -137,7 +137,8 @@
 - name: Install docker SDK for python
   pip:
     # NOTE(hrw) docker 2.4.2 is in kolla-ansible requirements
-    name: docker>=2.4.2
+    # NOTE(mnasiadka): docker 5.0.0 lacks six in deps but requires it
+    name: docker>=2.4.2,<5.0.0
     executable: "{{ virtualenv is none | ternary('pip3', omit) }}"
     virtualenv: "{{ virtualenv is none | ternary(omit, virtualenv) }}"
     virtualenv_site_packages: "{{ virtualenv is none | ternary(omit, virtualenv_site_packages) }}"

releasenotes/notes/bug-1928915-482b2d53bb2a4d92.yaml

+---
+fixes:
+  - |
+    Fixed an issue where docker python SDK 5.0.0 was failing due to missing
+    six - introduced a constraint to install version lower than 5.x.
+    `LP#1928915 <https://launchpad.net/bugs/1928915>`__