Change long2ip return type

[jorgsowa]

The function inet_ntop cannot return false in the current usage, as was described https://github.com/vimeo/psalm/pull/9537#discussion_r1140799451.

[devnexen]

test failing on windows seem related

[ndossche]

It fails because the assertion may be deleted and so the function call too.
Split the call from the assertion: store the result of the call in a variable, and do the assertion on the variable

[devnexen]

Look ok otherwise.

[devnexen]

Would it be possible to squash your commits ?

[kocsismate]

@devnexen It is possible to squash the commits on the GitHub UI. Since the MR looks good to me as well, I'll do it.

[jorgsowa]

Thanks!