Add ReturnTypeWillChange to FrameCollection

Fix PHP 8.1 compatibility

src/Whoops/Exception/FrameCollection.php

@@ -10,6 +10,7 @@ use ArrayAccess;
 use ArrayIterator;
 use Countable;
 use IteratorAggregate;
+use ReturnTypeWillChange;
 use Serializable;
 use UnexpectedValueException;
 
@@ -89,6 +90,7 @@ class FrameCollection implements ArrayAccess, IteratorAggregate, Serializable, C
      * @see IteratorAggregate::getIterator
      * @return ArrayIterator
      */
+    #[ReturnTypeWillChange]
     public function getIterator()
     {
         return new ArrayIterator($this->frames);
@@ -98,6 +100,7 @@ class FrameCollection implements ArrayAccess, IteratorAggregate, Serializable, C
      * @see ArrayAccess::offsetExists
      * @param int $offset
      */
+    #[ReturnTypeWillChange]
     public function offsetExists($offset)
     {
         return isset($this->frames[$offset]);
@@ -107,6 +110,7 @@ class FrameCollection implements ArrayAccess, IteratorAggregate, Serializable, C
      * @see ArrayAccess::offsetGet
      * @param int $offset
      */
+    #[ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         return $this->frames[$offset];
@@ -116,6 +120,7 @@ class FrameCollection implements ArrayAccess, IteratorAggregate, Serializable, C
      * @see ArrayAccess::offsetSet
      * @param int $offset
      */
+    #[ReturnTypeWillChange]
     public function offsetSet($offset, $value)
     {
         throw new \Exception(__CLASS__ . ' is read only');
@@ -125,6 +130,7 @@ class FrameCollection implements ArrayAccess, IteratorAggregate, Serializable, C
      * @see ArrayAccess::offsetUnset
      * @param int $offset
      */
+    #[ReturnTypeWillChange]
     public function offsetUnset($offset)
     {
         throw new \Exception(__CLASS__ . ' is read only');
@@ -134,6 +140,7 @@ class FrameCollection implements ArrayAccess, IteratorAggregate, Serializable, C
      * @see Countable::count
      * @return int
      */
+    #[ReturnTypeWillChange]
     public function count()
     {
         return count($this->frames);
@@ -155,6 +162,7 @@ class FrameCollection implements ArrayAccess, IteratorAggregate, Serializable, C
      * @see Serializable::serialize
      * @return string
      */
+    #[ReturnTypeWillChange]
     public function serialize()
     {
         return serialize($this->frames);
@@ -164,6 +172,7 @@ class FrameCollection implements ArrayAccess, IteratorAggregate, Serializable, C
      * @see Serializable::unserialize
      * @param string $serializedFrames
      */
+    #[ReturnTypeWillChange]
     public function unserialize($serializedFrames)
     {
         $this->frames = unserialize($serializedFrames);