Use separate nodeProjectDir per project

Using a shared nodeProjectDir caused multiple nodeSetup tasks to step on each others' toes. The com.github.node-gradle.node plugin doesn't fully support reusing nodeProjectDir, and each nodeSetup task will clean up the existing nodeProjectDir before unpacking the node installation into it. This can result in tasks seeing issues when trying to use npm/node while a nodeSetup task from another project is cleaning it up.

use nodeProjectDir instead of rootNodeDir

gradle/node.gradle

@@ -35,8 +35,7 @@ configure([project(":solr:packaging"), project(":solr:solr-ref-guide"), project(
     }
 
     project.ext {
-        rootNodeDir = "$rootDir/.gradle/node"
-        nodeProjectDir = file("$rootNodeDir/$project.name")
+        nodeProjectDir = layout.projectDirectory.dir(".gradle/node")
     }
 
     node {
@@ -49,10 +48,10 @@ configure([project(":solr:packaging"), project(":solr:solr-ref-guide"), project(
         }
 
         // The directory where Node.js is unpacked (when download is true)
-        workDir = file("${project.ext.rootNodeDir}/nodejs")
+        workDir = file("${project.ext.nodeProjectDir.getAsFile().path}/nodejs")
 
         // The directory where npm is installed (when a specific version is defined)
-        npmWorkDir = file("${project.ext.rootNodeDir}/npm")
+        npmWorkDir = file("${project.ext.nodeProjectDir.getAsFile().path}/npm")
 
         // The Node.js project directory location
         // This is where the package.json file and node_modules directory are located