Run trixie test with a trixie float-runner

Try a recent Ansible version to deal with targets having Python 3.12.

.gitlab-ci.yml

@@ -59,6 +59,8 @@ base_test:
 
 trixie_test:
   <<: *base_test
+  # Need a more recent Ansible version, for Python 3.12 targets.
+  image: registry.git.autistici.org/ai3/docker/float-runner:trixie
   variables:
     VM_IMAGE: "trixie"
     CREATE_ENV_VARS: "-e config.float_debian_dist=trixie"