Check if Phan has signatures for undeclared functions, classes, etc. in newer php versions

[TysonAndre]

<?php
// Observed: PhanUndeclaredFunction Call to undeclared function \str_contains()
// Expected: PhanUndeclaredFunction Call to undeclared function \str_contains() (This function was added in PHP 8.0, but Phan was invoked with php 7.2 and configured target_php_version 7.2)
return str_contains('foo', 'f');