[JS] Define Node.js version in one place and use a single version everywhere

Consequently, it fixes the inability to run some JS related tests on Apple devices with ARM.

js/js.tests/build.gradle.kts

@@ -14,7 +14,7 @@ plugins {
 
 node {
     download.set(true)
-    version.set("10.16.2")
+    version.set(nodejsVersion)
     nodeProjectDir.set(buildDir)
 }