Do not remove LF character at the EOF

[Andrew15-5]

• [x] I have tested with the master version of typstfmt and not just typst-lsp

Describe the bug

% in zsh's output means that the end of output is at the end of the line where % is, meaning that there is no LF at the end of this line.

If i chat print file's output, no % is shown:

To Reproduce Steps to reproduce the behavior: echo word | typstfmt --output - (echo always adds LF at the end of the line). This will output: