Remove fallback for controller location (#47104)

This change removes the temporary controller
location fallback introduced in #47013.

Relates elastic/ml-cpp#593

Author: David Roberts

server/src/main/java/org/elasticsearch/bootstrap/Spawner.java

@@ -72,13 +72,9 @@ void spawnNativeControllers(final Environment environment) throws IOException {
         List<Path> paths = PluginsService.findPluginDirs(environment.modulesFile());
         for (final Path modules : paths) {
             final PluginInfo info = PluginInfo.readFromProperties(modules);
-            Path spawnPath = Platforms.nativeControllerPath(modules);
+            final Path spawnPath = Platforms.nativeControllerPath(modules);
             if (!Files.isRegularFile(spawnPath)) {
-                // TODO: remove before release and just continue if the controller is not in the standard place
-                spawnPath = Platforms.fallbackNativeControllerPath(modules);
-                if (spawnPath == null || Files.isRegularFile(spawnPath) == false) {
-                    continue;
-                }
+                continue;
             }
             if (!info.hasNativeController()) {
                 final String message = String.format(

server/src/main/java/org/elasticsearch/plugins/Platforms.java

@@ -54,25 +54,6 @@ public static Path nativeControllerPath(Path plugin) {
                 .resolve(PROGRAM_NAME);
     }
 
-    /**
-     * The fallback path to the native controller for a plugin with native
-     * components to be used if no program is found using the standard path.
-     * This is a temporary measure to allow developers not working on this
-     * functionality to continue to work with C++ bundles from before or
-     * after the change. This code should never be in a supported release.
-     * TODO: remove this method before release
-     */
-    public static Path fallbackNativeControllerPath(Path plugin) {
-        if (Constants.MAC_OS_X) {
-            return plugin
-                .resolve("platform")
-                .resolve(PLATFORM_NAME)
-                .resolve("bin")
-                .resolve(PROGRAM_NAME);
-        }
-        return null;
-    }
-
     /**
      * Return the platform name based on the OS name and architecture, for example:
      * - darwin-x86_64