Update some Docker image references

docs/ansible.md

@@ -51,7 +51,7 @@ docker run -it --rm \
 -v `pwd`:/work \
 -v $HOME/.ssh/id_rsa:/root/.ssh/id_rsa:ro \
 --entrypoint=/bin/sh \
-devture/ansible:2.9.13-r0
+docker.io/devture/ansible:2.9.14-r0
 ```
 
 The above command tries to mount an SSH key (`$HOME/.ssh/id_rsa`) into the container (at `/root/.ssh/id_rsa`).

docs/maintenance-postgres.md

@@ -45,7 +45,7 @@ docker run \
 --log-driver=none \
 --network=matrix \
 --env-file=/matrix/postgres/env-postgres-psql \
-postgres:13.0-alpine \
+docker.io/postgres:13.1-alpine \
 pg_dumpall -h matrix-postgres \
 | gzip -c \
 > /postgres.sql.gz