Configuration cache compatibility

[ov7a]

Plugin version 0.14 became incompatible with the configuration cache.

FAILURE: Build failed with an exception.

* What went wrong:
Configuration cache problems found in this build.

1 problem was found storing the configuration cache.
- Task `:compilePlayRoutes` of type `org.gradle.playframework.tasks.RoutesCompile`: invocation of 'Task.project' at execution time is unsupported.
  See https://docs.gradle.org/8.3-20230710200000+0000/userguide/configuration_cache.html#config_cache:requirements:use_project_during_execution

See the complete report at file:///Users/ov7a/work/gradle_copy/subprojects/smoke-test/build/tmp/te%C5%9Dt%20files/PlayExterna.Test/bbyb/build/reports/configuration-cache/ceytd1kss4ltxedelko6wj4po/4le2nn5j2bwz0jgy3sia0k46i/configuration-cache-report.html
> Invocation of 'Task.project' by task ':compilePlayRoutes' at execution time is unsupported.

0.13 works fine.

This can be reproduced with Gradle's smoke tests

Most probably the problem was introduced with this line