Bug report

if the length of a string is 1, it is not necessarily truthy. if it is '0', the string is fasly

Code snippet that reproduces the problem

https://phpstan.org/r/0d0ff87d-1142-4c8d-887a-9ea257c0540b
https://phpstan.org/r/af765852-8582-480e-8225-6457ee0b214e
https://3v4l.org/BeHAV

Expected output

No errors