examples: bump images version

[luckydonald]

Updated dependency containers (traefik, mariadb, redis):

• traefik:2.10.4 -> 2.11.0
• mariadb:10.5 -> 11.3.2
• redis:4.0-alpine -> 7.2.4-alpine

Tested the traefik configuration with anonaddy:1.0.8.

That's also the reason why I didn't bump nginx, as I didn't test that example.
I only updated the tested images.