Squashed commits
----------------
* 28c5acf 2023-12-09 Zombaya  Allow symfony 7.x in root-composer-json and add demo project for symfony 7
* 47526a7 2023-12-09 Zombaya  Add demo-project using symfony 7.x
* e93cce7 2023-12-09 Zombaya  Use path of phpunit-bridge for symfony 4.x
* 2649be2 2023-12-09 Zombaya  Rework service-definitions and split it up in multiple files so we support sf 4.x-7.x
* d42637b 2023-12-09 Zombaya  Removed symfony 4.4 demo
* a05da56 2023-12-09 Zombaya  Add demo-project for sf 5.4
* d185546 2023-12-09 Zombaya  Replace sf 4.4 by 5.4 in CI
* a05b686 2023-12-09 Zombaya  Drop support for sf 4.* in composer.json
* 14362ff 2023-12-09 Zombaya  Allow halite 4.6 in sf 5.4-demo
* 388c358 2023-12-09 Zombaya  Use seperate config for php 8 and 7 in sf 5.4 demo
* 507e9b4 2023-12-09 Zombaya  Drop support for sf 4 in DoctrineEncryptExtension as well
* 9f23159 2023-12-09 Zombaya  Move dev-requirements and allow more versions of phpunit-bridge
* a4e79da 2023-12-09 Zombaya  Never use phpunit directly - only use the bridge
* 35add17 2023-12-09 Zombaya  Ignore tests in phpstan for now
* 0c8d2e0 2023-12-09 Zombaya  Use simple-php-unit for root-project
* aff5a52 2023-12-09 Zombaya  Stop forcing phpunit version for phpunit-bridge in 5.4-demo
* 3172c8a 2023-12-09 Zombaya  Remove forced version for php 7.2 for composer
* b74e4fb 2023-12-09 Zombaya  Require recent version of phpunit-bridge for root-project
* 53260f6 2023-12-09 Zombaya  Remove lowest for now
* d414bb8 2023-12-09 Zombaya  Add CI-run for demo 7.x
* f58810f 2023-12-09 Zombaya  Restrict CI for sf7 to php 8.2
* a1189b2 2024-02-26 Zombaya  Small cleanup after review
* 7ce2724 2024-02-26 Zombaya  Small fix for missing rename of file

From the documentation:
> The PHPUnit bridge is designed to work with all maintained versions of Symfony components,
> even across different major versions of them.
> You should always use its very latest stable major version to get the most accurate deprecation report.

Changes
=======

* Set variable to use correct phpunit to run on lowest
  See symfony/symfony#52844
* Up the minimum-requirement for symfony/flex for demo/sf5.4 to 1.21
* Update minimal version of doctrine/doctrine-bundle to allow installing with prefer-lowest on sf 5.4