public function offsetSet($offset, $value)                                                                                                                                                                                        
public function offsetUnset($offset)                                                                                                                                                                                              
                                                                                                                                                                                                                                  
With PHP 8.4 we get deprecation notices like:                                                                                                                                                                                     
                                                                                                                                                                                                                                  
- Method "ArrayAccess::offsetSet()" might add "void" as a native return type declaration in the future. Do the same in implementation "Opis\String\UnicodeString" now to avoid errors or add an explicit @return annotation to    
  suppress this message.                                                                                                                                                                                                          
- Method "ArrayAccess::offsetUnset()" might add "void" as a native return type declaration in the future. Do the same in implementation "Opis\String\UnicodeString" now to avoid errors or add an explicit @return annotation to  
  suppress this message.                                                                                                                                                                                                          
                                                                                                                                                                                                                                  
From our side this is reproducible while using opis/json-schema, because it pulls in opis/string.