Avoid Gradle deprecation warnings

[noojung]

Running the build and config module tests with --warning-mode=all reports the following deprecation warnings:

> Configure project :spring-security-bom
Using a Project object as a dependency constraint notation has been deprecated. This will fail with an error in Gradle 10. Please use the project(String) method on DependencyHandler or the createProjectDependency(String) method on DependencyFactory instead. Consult the upgrading guide for further information: https://docs.gradle.org/9.7.1/userguide/upgrading_version_9.html#dependency_project_notation

> Configure project :spring-security-docs
Using a Project object as a dependency notation has been deprecated. This will fail with an error in Gradle 10. Please use the project(String) method on DependencyHandler or the createProjectDependency(String) method on DependencyFactory instead. Consult the upgrading guide for further information: https://docs.gradle.org/9.7.1/userguide/upgrading_version_9.html#dependency_project_notation

> Configure project :spring-security-config
The AbstractTestTask.onOutput(Closure) method has been deprecated. This is scheduled to be removed in Gradle 10. Please use the addTestOutputListener(TestOutputListener) method instead. Consult the upgrading guide for further information: https://docs.gradle.org/9.7.1/userguide/upgrading_version_9.html#deprecated_test_methods

> Task :spring-security-config:test
Invocation of Task.project at execution time has been deprecated. This will fail with an error in Gradle 10. This API is incompatible with the configuration cache, which will become the only mode supported by Gradle in a future release. Consult the upgrading guide for further information: https://docs.gradle.org/9.7.1/userguide/upgrading_version_7.html#task_project

These usages will become errors in Gradle 10.

This PR updates the following:

• spring-security-bom.gradle and DocsPlugin use DependencyFactory.createProjectDependency(...) instead of passing Project instances as dependency and dependency constraint notation.
• spring-security-config.gradle replaces the deprecated AbstractTestTask.onOutput(Closure) method with addTestOutputListener.
• spring-security-config.gradle also replaces project.hasProperty('serialization') with providers.gradleProperty('serialization').isPresent() in the listener, avoiding execution-time access to Task.project.

References:

• Deprecation of using Project objects as dependency notation
• Deprecation of methods taking Closure on Test tasks
• Calling Task.getProject() from a task action