Test gitea 1.16 partial clones

Gitea 1.16 enabled clone filters by default. Unfortunately pip passes
--filter=blob:none when fetching git resources and the new gitea support
for filters breaks against that filter. We are working around this by
restoring the 1.15 behavior of not supporting filters and this change
will test the behavior is as expected.

Change-Id: I13d57e3cc7e135058ff320b3bd9bea76fb178064

playbooks/test-gitea.yaml

@@ -48,6 +48,10 @@
         cd /home/zuul/src/opendev.org/opendev/system-config
         git remote add test-gitea ssh://git@localhost:222/opendev/system-config
         GIT_SSH_COMMAND='ssh -i /home/zuul/.ssh/id_ed25519' git push -f test-gitea master
+    - name: Clone system-config to check that partial clones aren't breaking stuff
+      shell: |
+        cd /tmp
+        GIT_SSL_NO_VERIFY=1 git clone --filter=blob:none https://localhost:3081/opendev/system-config test-system-config-clone
 
 - name: Run rename playbook
   import_playbook: rename_repos.yaml