Bug report

Concatenation of two literal-strings will make the result a literal-string as well, but using string interpolation it does not make the result a literal-string, but instead makes it a non-empty-string.

Code snippet that reproduces the problem

https://phpstan.org/r/c3a9d482-2963-4711-949c-7c387c2aff89

Expected output

I would expect no error from the string interpolation, and allow it to continue as a literal-string. Maybe I'm missing something though and this is intended behavior, let me know what you think.

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Congratulations with reaching version 1 😄 , looking forward to using all features of it (I already have a couple of them enabled using experimental flags of the previous version)