Remove the need for AllowDynamicProperties in LazyOpenStream (#547)

src/LazyOpenStream.php

@@ -10,7 +10,6 @@
  * Lazily reads or writes to a file that is opened only after an IO operation
  * take place on the stream.
  */
-#[\AllowDynamicProperties]
 final class LazyOpenStream implements StreamInterface
 {
     use StreamDecoratorTrait;
@@ -21,6 +20,11 @@ final class LazyOpenStream implements StreamInterface
     /** @var string */
     private $mode;
 
+    /**
+     * @var StreamInterface
+     */
+    private $stream;
+
     /**
      * @param string $filename File to lazily open
      * @param string $mode     fopen mode to use when opening the stream
@@ -29,6 +33,10 @@ public function __construct(string $filename, string $mode)
     {
         $this->filename = $filename;
         $this->mode = $mode;
+
+        // unsetting the property forces the first access to go through
+        // __get().
+        unset($this->stream);
     }
 
     /**