PackageToJS: Fix skeleton file discovery path for build plugin output

The SkeletonCollector was looking for BridgeJS.json at the wrong path
for build-time generated files. Since commit 91d2f06, BridgeJSTool
writes skeleton files to `destination/BridgeJS/JavaScript/BridgeJS.json`,
but PackageToJS was searching in `destination/BridgeJS/BridgeJS.json`
(missing the JavaScript/ subdirectory).

This caused projects using dynamic BridgeJS generation via the build
plugin to fail - PackageToJS couldn't find the skeleton files, resulting
in HAS_BRIDGE=false and stub implementations in instantiate.js.

Author: krodak

Plugins/PackageToJS/Sources/PackageToJSPlugin.swift

@@ -751,9 +751,9 @@ class SkeletonCollector {
             let directories = [
                 target.directoryURL.appending(path: "Generated/JavaScript"),
                 // context.pluginWorkDirectoryURL: ".build/plugins/PackageToJS/outputs/"
-                // .build/plugins/outputs/exportswift/MyApp/destination/BridgeJS/BridgeJS.ExportSwift.json
+                // .build/plugins/outputs/[package]/[target]/destination/BridgeJS/JavaScript/BridgeJS.json
                 context.pluginWorkDirectoryURL.deletingLastPathComponent().deletingLastPathComponent()
-                    .appending(path: "outputs/\(package.id)/\(target.name)/destination/BridgeJS"),
+                    .appending(path: "outputs/\(package.id)/\(target.name)/destination/BridgeJS/JavaScript"),
             ]
             for directory in directories {
                 let skeletonURL = directory.appending(path: skeletonFile)