Re-enable driver agent for scenario 13

It is follow up for the patch [1] which did the same thing for scenario
10.

[1] https://review.opendev.org/#/c/714639

Change-Id: Id834e80370eedac8ad32212490975b39c8a18afc

ci/environments/scenario013-standalone.yaml

@@ -31,9 +31,6 @@ parameter_defaults:
   OctaviaCaKeyPassphrase: 'upstreamci'
   OctaviaManageNovaFlavor: true
   OctaviaGenerateCerts: true
-  # TODO(cgoncalves): re-enable once RDO package ovn-octavia-provider is available (https://review.rdoproject.org/r/#/c/25972/)
-  #                   and installed in Kolla container
-  OctaviaEnableDriverAgent: false
   Debug: true
   GlanceBackend: 'file'
   ContainerCli: podman