"precommit" on SQL security "with-ssl" and "without-ssl" projects fails after a "gradle clean"

[astefan]

To reproduce this:

1. gradlew clean
2. gradlew :x-pack:plugin:sql:qa:security:without-ssl:precommit --parallel
   or
   gradlew :x-pack:plugin:sql:qa:security:with-ssl:precommit --parallel

This will fail with

> Task :x-pack:plugin:sql:qa:security:without-ssl:testingConventions FAILED
Expected at least one test class included in task :x-pack:plugin:sql:qa:security:without-ssl:integTestRunner, but found none.

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':x-pack:plugin:sql:qa:security:without-ssl:testingConventions'.
> Testing conventions are not honored

Digging into this a bit, it seems the PR that fixed #40550 seems to be the one that introduced the behavior above.

CC @mark-vieira @atorok

[elasticmachine]

Pinging @elastic/es-core-infra