Explicitly adds the JUnit Platform Launcher as a test runtime dependency

This fix is to address the deprecation warning that occurs when running tests.

This solution follows the recommended approach from the Gradle documentation and should resolve the deprecation warning while maintaining the same test functionality.

Author: robsyme

plugins/nf-hello/build.gradle

@@ -78,10 +78,43 @@ dependencies {
     modules {
         module("commons-logging:commons-logging") { replacedBy("org.slf4j:jcl-over-slf4j") }
     }
+
+    // Add this line to explicitly declare the test framework launcher
+    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
 }
 
 // use JUnit 5 platform
 test {
     useJUnitPlatform()
 }
 
+// Task to install the plugin to the Nextflow plugins directory
+task installPlugin(type: Copy, dependsOn: copyPluginZip) {
+    def pluginsDir = System.getenv('NXF_PLUGINS_DIR') ?:
+                     System.getenv('NXF_HOME') ? "${System.getenv('NXF_HOME')}/plugins" :
+                     "${System.getProperty('user.home')}/.nextflow/plugins"
+    
+    def pluginZip = file("$rootProject.buildDir/plugins/${project.name}-${project.version}.zip")
+    def pluginDir = file("$pluginsDir/${project.name}-${project.version}")
+
+    doFirst {
+        println "Installing plugin to: $pluginDir"
+        pluginDir.mkdirs()
+    }
+
+    from zipTree(pluginZip)
+    into pluginDir
+
+    doLast {
+        println "Plugin installed successfully!"
+        println "Installation location determined by:"
+        if (System.getenv('NXF_PLUGINS_DIR')) {
+            println " - NXF_PLUGINS_DIR environment variable"
+        } else if (System.getenv('NXF_HOME')) {
+            println " - NXF_HOME environment variable"
+        } else {
+            println " - Default location (~/.nextflow/plugins)"
+        }
+    }
+}
+