pdf2md returns an empty markdown for some files in Japanese

**Description** pdf2md returns an empty markdown for the following file: [tax_template.pdf](https://github.com/user-attachments/files/19281790/1.pdf) However, https://pdf2md.morethan.io/ (https://github.com/jzillmann/pdf-to-markdown) manages to read the PDF file and convert it to markdown. **To Reproduce** ``` import pdf2md from '@opendocsg/pdf2md'; import { readFileSync, writeFileSync } from 'fs'; const file = readFileSync('tax_template.pdf'); const markdownText = await pdf2md(file); console.log('markdownText', markdownText); writeFileSync('tax_template.md', markdownText); ``` **Expected behavior** pdf2md returns a non empty markdown, like https://pdf2md.morethan.io/ **Misc** OS: macOS 15.3.2 node.js v20.18.1 pdf2md 0.2.1