Ability to select multiple test frameworks for a test suite

[Vampire]

In Gradle 7.5 you can only select one test framework using the API and would have to setup other frameworks manually.
It would be nice if you for example could call useJUnitJupiter() and useSpock() and then have both frameworks available directly.

[tresat]

@ghale - Do you think we should close this? It doesn't seem like something we plan on supporting.

[big-guy]

So other people can see it, this is something we're actively planning/discussing in a slightly different form:
https://docs.google.com/document/d/1jH3pdRxx-fnvFiq6evVdRHCGEfcWgOjfvCiSUWfCzQM/edit

We want to support a test suite having multiple test engines (on the JUnit platform).

We do not want to support mixing entirely different testing frameworks (e.g., testng + junit4) that do not run on the JUnit platform.