Update php requirement to >=8.1 and upgrade twig/twig to ^3.11.2

[poespas]

Fixes current problem:

Problem 1
    - Root composer.json requires twig/twig ^2.12, found twig/twig[v2.12.0, ..., v2.16.1] but these were not loaded, because they are affected by security advisories. To ignore the advisories, add ("PKSA-yhcn-xrg3-68b1", "PKSA-2wrf-1xmk-1pky") to the audit "ignore" config. To turn the feature off entirely, you can set "block-insecure" to false in your "audit" config.

Also removed version from docker-compose.yaml, as that seems to be strongly requested (error)