chore: fix return type will change deprecation in PHP 8.1

src/vierbergenlars/LibJs/JSArray.php

@@ -149,49 +149,57 @@ public function __get($name)
         }
     }
 
-
+    #[\ReturnTypeWillChange]
     public function current()
     {
         return $this->_convert(current($this->array));
     }
 
+    #[\ReturnTypeWillChange]
     public function key()
     {
         return $this->_convert(key($this->array));
     }
 
+    #[\ReturnTypeWillChange]
     public function next()
     {
         return $this->_convert(next($this->array));
     }
 
+    #[\ReturnTypeWillChange]
     public function offsetExists($offset)
     {
         return isset($this->array[$offset]);
     }
 
+    #[\ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         if(!$this->offsetExists($offset))
             return null;
         return $this->_convert($this->array[$offset]);
     }
 
+    #[\ReturnTypeWillChange]
     public function offsetSet($offset, $value)
     {
         $this->array[$offset] = $value;
     }
 
+    #[\ReturnTypeWillChange]
     public function offsetUnset($offset)
     {
         unset($this->array[$offset]);
     }
 
+    #[\ReturnTypeWillChange]
     public function rewind()
     {
         return reset($this->array);
     }
 
+    #[\ReturnTypeWillChange]
     public function valid()
     {
         return key($this->array) !== null;

src/vierbergenlars/LibJs/JString.php

@@ -207,21 +207,25 @@ public function __get($name)
         }
     }
 
+    #[\ReturnTypeWillChange]
     public function offsetExists($offset)
     {
         return isset($this->str[$offset]);
     }
 
+    #[\ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         return $this->str[$offset];
     }
 
+    #[\ReturnTypeWillChange]
     public function offsetSet($offset, $value)
     {
         $this->str[$offset] = $value;
     }
 
+    #[\ReturnTypeWillChange]
     public function offsetUnset($offset)
     {
         throw new \LogicException('Cannot unset a position in a string');