Adjustments because traverseModules no longer returns depth

We no longer need `depth`. Adopt a faster version of `traverseModules` that doesn’t return the depth.

rdar://136107035

Author: ahoppen

Sources/BuildSystemIntegration/SwiftPMBuildSystem.swift

@@ -404,7 +404,7 @@ package actor SwiftPMBuildSystem: BuiltInBuildSystem {
     self.swiftPMTargets = [:]
     self.targetDependencies = [:]
 
-    buildDescription.traverseModules { buildTarget, parent, depth in
+    buildDescription.traverseModules { buildTarget, parent in
       let targetIdentifier = orLog("Getting build target identifier") { try BuildTargetIdentifier(buildTarget) }
       guard let targetIdentifier else {
         return