ci: Restart docker before run

Also, add setting for persistent worker in .cirrus.yml

.cirrus.yml

@@ -10,6 +10,12 @@ env:
 cirrus_ephemeral_worker_template_env: &CIRRUS_EPHEMERAL_WORKER_TEMPLATE_ENV
   DANGER_RUN_CI_ON_HOST: "1"  # Containers will be discarded after the run, so there is no risk that the ci scripts modify the system
 
+persistent_worker_template_env: &PERSISTENT_WORKER_TEMPLATE_ENV
+  RESTART_CI_DOCKER_BEFORE_RUN: "1"
+
+persistent_worker_template: &PERSISTENT_WORKER_TEMPLATE
+  persistent_worker: {}  # https://cirrus-ci.org/guide/persistent-workers/
+
 # https://cirrus-ci.org/guide/tips-and-tricks/#sharing-configuration-between-tasks
 base_template: &BASE_TEMPLATE
   skip: $CIRRUS_REPO_FULL_NAME == "bitcoin-core/gui" && $CIRRUS_PR == ""  # No need to run on the read-only mirror, unless it is a PR. https://cirrus-ci.org/guide/writing-tasks/#conditional-task-execution

ci/test/04_install.sh

@@ -33,7 +33,12 @@ if [ -z "$DANGER_RUN_CI_ON_HOST" ]; then
   echo "Creating $DOCKER_NAME_TAG container to run in"
   ${CI_RETRY_EXE} docker pull "$DOCKER_NAME_TAG"
 
-  DOCKER_ID=$(docker run $DOCKER_ADMIN -idt \
+  if [ -n "${RESTART_CI_DOCKER_BEFORE_RUN}" ] ; then
+    echo "Restart docker before run to stop and clear all containers started with --rm"
+    systemctl restart docker
+  fi
+
+  DOCKER_ID=$(docker run $DOCKER_ADMIN --rm --interactive --detach --tty \
                   --mount type=bind,src=$BASE_ROOT_DIR,dst=/ro_base,readonly \
                   --mount type=bind,src=$CCACHE_DIR,dst=$CCACHE_DIR \
                   --mount type=bind,src=$DEPENDS_DIR,dst=$DEPENDS_DIR \