Shard/parallelize the integration tests #2743

Description

Unfortunately looking at the Spock documentation I could not find a way to easily shard tests like with Playwright.

So we could try do build our own simple sharding solution like Playwright, by counting all test files and splitting those over multiple shards.

The more ideal solution I would think is finding a way to isolate the tests in full.

Alternatively we could attempt to use https://java.testcontainers.org/

Acceptance Criteria

• 1. [Criteria]

Implementation Notes

I would think the ideal solution would be to isolate the tests by provisioning the postgres container with multiple test databases dynamically per test file or even test. This avoids the potential overhead of creating multiple test containers and should hopefully be isolated enough. Would need to look into whether something like that is feasable. I think this would be nice to pair with #2222