Try to avoid Docker logs growing too much for one-off containers

We recently had a report of the Postgres backup container's log file
growing the size of /var/lib/docker until it ran out of disk space.

Trying to prevent similar problems in the future.

docs/maintenance-postgres.md

@@ -42,6 +42,7 @@ To make a back up of the current PostgreSQL database, make sure it's running and
 ```bash
 docker run \
 --rm \
+--log-driver=none \
 --network=matrix \
 --env-file=/matrix/postgres/env-postgres-psql \
 postgres:12.4-alpine \

roles/matrix-postgres/tasks/import_postgres.yml

@@ -64,6 +64,7 @@
   set_fact:
     matrix_postgres_import_command: >-
       {{ matrix_host_command_docker }} run --rm --name matrix-postgres-import
+      --log-driver=none
       --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
       --cap-drop=ALL
       --network={{ matrix_docker_network }}

roles/matrix-postgres/tasks/import_sqlite_db.yml

@@ -74,6 +74,7 @@
     docker run
     --rm
     --name=matrix-synapse-migrate
+    --log-driver=none
     --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
     --cap-drop=ALL
     --network={{ matrix_docker_network }}

roles/matrix-postgres/tasks/upgrade_postgres.yml

@@ -80,6 +80,7 @@
 - name: Perform Postgres database dump
   command: >-
     {{ matrix_host_command_docker }} run --rm --name matrix-postgres-dump
+    --log-driver=none
     --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
     --network={{ matrix_docker_network }}
     --env-file={{ matrix_postgres_base_path }}/env-postgres-psql
@@ -124,6 +125,7 @@
   set_fact:
     matrix_postgres_import_command: >-
       {{ matrix_host_command_docker }} run --rm --name matrix-postgres-import
+      --log-driver=none
       --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
       --cap-drop=ALL
       --network={{ matrix_docker_network }}