openqa etc: reinstall local Python libs when Python ver changes

In openqa/dispatcher, relvalconsumer and check-compose roles, we
install Python libraries from git checkouts (these are things we
don't really want to package as they change too much). This
enhances those roles so that we check whether pip considers the
libraries to be installed, and install them if it doesn't. The
purpose is to catch when the Python version rolls over on system
upgrade, and reinstall the libraries in that case - I got bitten
by this when upgrading to F32, I forgot to reinstall these libs
for Python 3.8, and it broke things for a couple of days before
I noticed and fixed it manually...

Signed-off-by: Adam Williamson <awilliam@redhat.com>

roles/relvalconsumer/tasks/main.yml

@@ -107,7 +107,7 @@
     # 'relval' itself is needed as we call it directly for size
     # checking
     name: ['python3-fedfind', 'python3-wikitcms', 'fedora-messaging',
-           'python3-mwclient', 'python3-setuptools', 'relval']
+           'python3-mwclient', 'python3-pip', 'python3-setuptools', 'relval']
     state: present
   tags:
   - packages
@@ -140,11 +140,18 @@
     dest: /root/relvalconsumer
   register: gitrvc
 
+- name: Check if relvalconsumer is installed for current Python
+  command: "pip show relvalconsumer"
+  register: instrvc
+  changed_when: "1 != 1"
+  failed_when: "1 != 1"
+  check_mode: no
+
 - name: Install relvalconsumer
   command: "python3 setup.py install --nodeps"
   args:
     chdir: /root/relvalconsumer
-  when: "gitrvc is changed"
+  when: "gitrvc is changed or instrvc.rc != 0"
   notify:
   - restart relvalconsumer