Fail to aggregate after serenity-gradle-plugin upgrade from 4.0.46 to 4.2.1

What happened?

PRELIMINARY. More work on my side required to narrow down the cause.
CURRENTLY CHECKING dependency changes, including junit.

Migrating from 4.0.46 to 4.2.1, the aggregate step fails and gradle reports missing properties. I have a slightly modified aggregate task that worked in 4.1.14 and earlier. Looked through the source and don't see relevant changes in serenty. Gradle version 8.7 (unchanged). Properties reported as not configured:

generateOutcomes
projectKey
reportDirectory

Log snippet: ... SAVING TEST RESULTS for ... .xml FAILURE: Build failed with an exception.

What went wrong: Some problems were found with the configuration of task ':aggregateBANK' (type 'AggregateTask').
- In plugin 'net.serenity-bdd.serenity-gradle-plugin' type 'net.serenitybdd.plugins.gradle.AggregateTask' property 'generateOutcomes' doesn't have a configured value.
Reason: This property isn't marked as optional and no value has been configured.

Possible solutions:
1. Assign a value to 'generateOutcomes'.
2. Mark property 'generateOutcomes' as optional.
For more information, please refer to https://docs.gradle.org/8.7/userguide/validation_problems.html#value_not_set in the Gradle documentation.
- In plugin 'net.serenity-bdd.serenity-gradle-plugin' type 'net.serenitybdd.plugins.gradle.AggregateTask' property 'projectKey' doesn't have a configured value.
Reason: This property isn't marked as optional and no value has been configured.

Possible solutions:
1. Assign a value to 'projectKey'.
2. Mark property 'projectKey' as optional.
For more information, please refer to https://docs.gradle.org/8.7/userguide/validation_problems.html#value_not_set in the Gradle documentation.
- In plugin 'net.serenity-bdd.serenity-gradle-plugin' type 'net.serenitybdd.plugins.gradle.AggregateTask' property 'reportDirectory' doesn't have a configured value.
Reason: This property isn't marked as optional and no value has been configured.

Possible solutions:
1. Assign a value to 'reportDirectory'.
2. Mark property 'reportDirectory' as optional.
For more information, please refer to https://docs.gradle.org/8.7/userguide/validation_problems.html#value_not_set in the Gradle documentation.

Will continue to investigate and update as possible.

What did you expect to happen?

Expected aggregate task to generate report successfully.

Serenity BDD version

4.2.1

JDK version

17.0.12 (Eclipse Adoptium 17.0.12+7)

Execution environment

Mac OS X 14.6.1 aarch64

RHEL openjdk version "17.0.8" 2023-07-18 LTS OpenJDK Runtime Environment (Red_Hat-17.0.8.0.7-1) (build 17.0.8+7-LTS) OpenJDK 64-Bit Server VM (Red_Hat-17.0.8.0.7-1) (build 17.0.8+7-LTS, mixed mode, sharing)

How to reproduce the bug.

./gradlew aggregate

How can we make it happen?

Work on this myself and propose a PR (with Serenity BDD team guidance)

serenity-bdd / serenity-core