Fix #1886 Sync error in ForgeGradle composite builds

Also remove duplicate tasks before executing them

Author: RedNesto

src/main/kotlin/platform/mcp/gradle/McpProjectResolverExtension.kt

@@ -59,7 +59,7 @@ class McpProjectResolverExtension : AbstractProjectResolverExtension() {
 
         val projectDirPath = Paths.get(projectDataNode.data.linkedExternalProjectPath)
         runGradleTask(project, projectDirPath) { settings ->
-            settings.taskNames = allTaskNames
+            settings.taskNames = allTaskNames.distinct()
         }
 
         super.resolveFinished(projectDataNode)

src/main/kotlin/platform/mcp/gradle/datahandler/McpModelFG3Handler.kt

@@ -34,6 +34,7 @@ import com.intellij.openapi.vfs.LocalFileSystem
 import org.gradle.tooling.model.idea.IdeaModule
 import org.jetbrains.plugins.gradle.model.data.GradleSourceSetData
 import org.jetbrains.plugins.gradle.service.project.ProjectResolverContext
+import org.jetbrains.plugins.gradle.util.gradleIdentityPath
 
 object McpModelFG3Handler : McpModelDataHandler {
 
@@ -68,9 +69,10 @@ object McpModelFG3Handler : McpModelDataHandler {
             forgeVersion,
         )
 
-        val gradleProjectPath = gradleModule.gradleProject.projectIdentifier.projectPath
-        val suffix = if (gradleProjectPath.endsWith(':')) "" else ":"
-        val taskName = gradleProjectPath + suffix + data.taskName
+        // gradleIdentityPath makes it work with composite builds
+        val identityPath = node.data.gradleIdentityPath
+        // But ignore it if it is the root project, as taskName already starts with a colon
+        val taskName = if (identityPath == ":") data.taskName else identityPath + ':' + data.taskName
 
         val ats = data.accessTransformers
         if (ats != null && ats.isNotEmpty()) {