[php-src] Issue #11967: Shutdown callback is affected by max execution time, but documentation says otherwise.

Issue: https://github.com/php/php-src/issues/11967 Author: Serchman ### Description It is reproducible here: https://www.tehplayground.com/PwpR764URQYi79Lj Resulted in this output: ``` Fatal error: Maximum execution time of 1 second exceeded in Standard input code on line 20 Start of shutdown Fatal error: Maximum execution time of 1 second exceeded in Standard input code on line 37 ``` But I expected this output instead: ``` Fatal error: Maximum execution time of 1 second exceeded in Standard input code on line 20 Start of shutdown End of shutdown ``` As per the documentation we would expect the shutdown callback to not be affected by any limits set. As documented here: https://www.php.net/manual/en/function.register-shutdown-function.php#:~:text=to%20end%20cleanly.-,Note%3A,while%20a%20shutdown%20function%20is%20running%20it%20will%20not%20be%20terminated.,-See%20Also%20%C2%B6 This is a problem for my usecase where if there is a Fatal error , in this case due to timeout, we want to run the shutdown function and not run into a timeout. ### PHP Version PHP Latest ### Operating System _No response_