Fix jsonSerialize() return type

Author: filippotoso

src/Messages/Outgoing/Actions/Button.php

@@ -126,6 +126,7 @@ public function toArray()
     /**
      * @return array
      */
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         return $this->toArray();

src/Messages/Outgoing/Actions/Select.php

@@ -92,6 +92,7 @@ public function toArray()
     /**
      * @return array
      */
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         return $this->toArray();

src/Messages/Outgoing/Question.php

@@ -113,6 +113,7 @@ public function toArray()
     /**
      * @return array
      */
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         return $this->toArray();