Fix Actions and update PHP matrix

[whikloj]

This includes the commits in #166, but also adds some tweaks based on phpstan runs and also adds PHP 8.2 and removes 7.3 from the build matrix.

I have left the

on:
  push:
    branches:
      - '**'

for now, I can remove it when you are ready. I can also re-add PHP 7.3 if you want to test it.

See here while it lasts for a test run.

Or you can ignore this and merge @danesteve's #166

[whikloj]

Oops I forgot that I moved the docker tags to be repository variables 🤦

ACTIVEMQ_IMAGE_TAG = 5.14.5-alpine

APOLLO_IMAGE_TAG = 1.7.1

ARTEMIS_IMAGE_TAG = 2.13.0-alpine

RABBITMQ_IMAGE_TAG = 3.6.11

[whikloj]

Rebasing so @danesteve's commits don't get collapsed into mine.