WIP - Introduce tests on platforms

[VincentLanglet]

Related to https://github.com/phpstan/phpstan-doctrine/pull/506#issuecomment-1944268880 @janedbal, I try to introduce tests on different platform. Does this solution would work for you ?

Edit: Are you also ok with this solution @ondrejmirtes ? I had in mind to provide @group platform on every platform tests, each with a special group like @group sql. And adding all different platform in github actions.

[janedbal]

The matrix (at some level) should also contain:

• driver (there are more for mysql and pgsql and some of them behave differently)
• config (mainly stringification on/off for PDO drivers)

[VincentLanglet]

The matrix (at some level) should also contain:

• config (mainly stringification on/off for PDO drivers)

Since the config must be passed to the entity manager in a entity-manager.php passed to phpstan in config with

parameters:
	doctrine:
		objectManagerLoader: entity-manager.php

I don't see how it would be in the matrix.

Currently, the only solution I see is to create one entityManager for every platform/config and one test case for every entityManager...