[2.x] fix: Remove projectDescriptors key that leaks Ivy types (#8894)

**Problem**
The projectDescriptors key in sbt.Keys leaked Ivy classes
(ModuleRevisionId, ModuleDescriptor) through its API surface.
No external plugins use this key.

**Solution**
Remove projectDescriptors entirely. IvyDependencyPlugin now uses
its internal depMap method directly for projectResolverTask and
coursierExtraProjectsTask, eliminating unnecessary Any casts.
The descriptors field is also removed from GlobalPluginData.

Fixes sbt#8865

build.sbt

@@ -745,6 +745,19 @@ lazy val mainProj = (project in file("main"))
       exclude[DirectMissingMethodProblem]("sbt.Classpaths.mkIvyConfiguration"),
       exclude[MissingClassProblem]("sbt.internal.librarymanagement.IvyXml"),
       exclude[MissingClassProblem]("sbt.internal.librarymanagement.IvyXml$"),
+      // Removed projectDescriptors key (sbt#8865)
+      exclude[DirectMissingMethodProblem]("sbt.Keys.projectDescriptors"),
+      // Removed descriptors field from GlobalPluginData (sbt#8865)
+      exclude[DirectMissingMethodProblem]("sbt.internal.GlobalPluginData.apply"),
+      exclude[DirectMissingMethodProblem]("sbt.internal.GlobalPluginData.this"),
+      exclude[DirectMissingMethodProblem]("sbt.internal.GlobalPluginData.descriptors"),
+      exclude[DirectMissingMethodProblem]("sbt.internal.GlobalPluginData.copy"),
+      exclude[IncompatibleResultTypeProblem]("sbt.internal.GlobalPluginData.copy$default$3"),
+      exclude[IncompatibleResultTypeProblem]("sbt.internal.GlobalPluginData.copy$default$4"),
+      exclude[DirectMissingMethodProblem]("sbt.internal.GlobalPluginData.copy$default$6"),
+      exclude[IncompatibleResultTypeProblem]("sbt.internal.GlobalPluginData._3"),
+      exclude[IncompatibleResultTypeProblem]("sbt.internal.GlobalPluginData._4"),
+      exclude[DirectMissingMethodProblem]("sbt.internal.GlobalPluginData._6"),
     ),
   )
   .dependsOn(lmCore, lmCoursierShadedPublishing)

main/src/main/scala/sbt/Defaults.scala

@@ -3134,7 +3134,6 @@ object Classpaths {
     makePom / artifact := Artifact.pom(moduleName.value),
     projectID := defaultProjectID.value,
     projectID := pluginProjectID.value,
-    projectDescriptors := Def.uncached(Map.empty[Any, Any]),
     updateConfiguration := {
       // Tell the UpdateConfiguration which artifact types are special (for sources and javadocs)
       val specialArtifactTypes = sourceArtifactTypes.value.toSet union docArtifactTypes.value.toSet

main/src/main/scala/sbt/Keys.scala

@@ -635,7 +635,6 @@ object Keys {
   @transient
   val publishTo = taskKey[Option[Resolver]]("The resolver to publish to.").withRank(ASetting)
   val artifacts = settingKey[Seq[Artifact]]("The artifact definitions for the current module.  Must be consistent with " + packagedArtifacts.key.label + ".").withRank(BSetting)
-  val projectDescriptors = taskKey[Map[Any, Any]]("Project dependency map for the inter-project resolver.").withRank(DTask)
   val autoUpdate = settingKey[Boolean]("<unimplemented>").withRank(Invisible)
   val retrieveManaged = settingKey[Boolean]("If true, enables retrieving dependencies to the current build.  Otherwise, dependencies are used directly from the cache.").withRank(BSetting)
   val retrieveManagedSync = settingKey[Boolean]("If true, enables synchronizing the dependencies retrieved to the current build by removed unneeded files.").withRank(BSetting)

main/src/main/scala/sbt/coursierint/CoursierInputsTasks.scala

@@ -103,7 +103,7 @@ object CoursierInputsTasks {
   private[sbt] def coursierExtraProjectsTask: Def.Initialize[sbt.Task[Seq[CProject]]] = {
     Def.task {
       // Coursier handles inter-project dependencies natively via csrInterProjectDependencies.
-      // The Ivy-typed projectDescriptors are only populated when IvyDependencyPlugin is enabled.
+      // When IvyDependencyPlugin is enabled, it overrides csrExtraProjects with Ivy descriptors.
       Seq.empty[CProject]
     }
   }

main/src/main/scala/sbt/internal/GlobalPlugin.scala

@@ -31,7 +31,6 @@ object GlobalPlugin {
   //  static here meaning that the relevant tasks for the global plugin have already been evaluated
   def inject(gp: GlobalPluginData): Seq[Setting[?]] =
     Seq[Setting[?]](
-      projectDescriptors ~= { _ ++ gp.descriptors },
       projectDependencies ++= gp.projectID +: gp.dependencies,
       resolvers := {
         val rs = resolvers.value
@@ -77,12 +76,10 @@ object GlobalPlugin {
     val taskInit = Def.task {
       val intcp = (Runtime / internalDependencyClasspath).value
       val prods = (Runtime / exportedProducts).value
-      val depMap = projectDescriptors.value
 
       GlobalPluginData(
         projectID.value,
         projectDependencies.value,
-        depMap,
         resolvers.value.toVector,
         (Runtime / fullClasspath).value,
         (prods ++ intcp).distinct
@@ -121,7 +118,6 @@ object GlobalPlugin {
 final case class GlobalPluginData(
     projectID: ModuleID,
     dependencies: Seq[ModuleID],
-    descriptors: Map[Any, Any],
     resolvers: Vector[Resolver],
     fullClasspath: Classpath,
     internalClasspath: Classpath

sbt-ivy/src/main/scala/sbt/plugins/IvyDependencyPlugin.scala

@@ -93,15 +93,6 @@ object IvyDependencyPlugin extends AutoPlugin:
         )
         .value
     ),
-    projectDescriptors := Def.uncached(
-      Def
-        .ifS(Def.task { useIvy.value })(
-          Def.task { depMap.value.asInstanceOf[Map[Any, Any]] }
-        )(
-          Def.task { Map.empty[Any, Any] }
-        )
-        .value
-    ),
     projectResolver := Def.uncached(
       Def
         .ifS(Def.task { useIvy.value })(
@@ -166,9 +157,8 @@ object IvyDependencyPlugin extends AutoPlugin:
     }
 
   private def projectResolverTask: Initialize[Task[Resolver]] =
-    projectDescriptors.map { m =>
-      val typedMap = m.asInstanceOf[Map[ModuleRevisionId, ModuleDescriptor]]
-      val resolver = new ProjectResolver(ProjectResolver.InterProject, typedMap)
+    depMap.map { m =>
+      val resolver = new ProjectResolver(ProjectResolver.InterProject, m)
       new RawRepository(resolver, resolver.getName)
     }
 
@@ -194,10 +184,8 @@ object IvyDependencyPlugin extends AutoPlugin:
     Def.task {
       val projects = csrInterProjectDependencies.value
       val projectModules = projects.map(_.module).toSet
-      projectDescriptors.value
-        .map { (k, v) =>
-          val id = k.asInstanceOf[ModuleRevisionId]
-          val desc = v.asInstanceOf[ModuleDescriptor]
+      depMap.value
+        .map { (id, desc) =>
           moduleFromIvy(id) -> desc
         }
         .filter { case (module, _) =>