perf: Re-use empty resource instance (#1251)

Author: PROFeNoM

src/SDK/Resource/ResourceInfoFactory.php

@@ -17,6 +17,8 @@ class ResourceInfoFactory
 {
     use LogsMessagesTrait;
 
+    private static ?ResourceInfo $emptyResource = null;
+
     public static function defaultResource(): ResourceInfo
     {
         $detectors = Configuration::getList(Env::OTEL_PHP_DETECTORS);
@@ -90,6 +92,10 @@ public static function defaultResource(): ResourceInfo
 
     public static function emptyResource(): ResourceInfo
     {
-        return ResourceInfo::create(Attributes::create([]));
+        if (null === self::$emptyResource) {
+            self::$emptyResource = ResourceInfo::create(Attributes::create([]));
+        }
+
+        return self::$emptyResource;
     }
 }