Skip AddMockitoJavaAgentToMavenSurefirePlugin when agent already configured in build/plugins

[timtebeek]

• Fixes AddMockitoJavaAgentToMavenSurefirePlugin recipe redundant argLine properties in multi module project #1164

Problem

In a multi-module project where the root pom declares the surefire plugin under build/plugins (not pluginManagement) with an argLine that already contains the Mockito javaagent, AddMockitoJavaAgentToMavenSurefirePlugin added a redundant empty <argLine></argLine> property to the root and every submodule (which inherit the plugin), instead of making no changes.

The early-return guard in visitDocument only inspected getPluginManagement(), so a surefire declaration in build/plugins was missed.

Fix

The guard now also returns early when the effective surefire plugin (declared locally or inherited via a parent's build/plugins) already carries the agent and the setup is complete:

• the supporting maven-dependency-plugin properties goal is present (needed to resolve ${org.mockito:mockito-core:jar}), and
• any @{argLine} reference can already resolve (an argLine property exists).

The existing pluginManagement blanket behavior is preserved, and scenarios where the agent is present but the properties goal is still missing continue to be completed by the recipe (covered by existing tests).

Testing

Added makesNoChangesWhenParentPomDeclaresSurefirePluginWithAgentConfiguration mirroring the reporter's minimal reproduction. All existing tests continue to pass.