Refactor PDF.js import to use dynamic import.

Switched from static to dynamic import for PDF.js to improve compatibility and possibly reduce initial load time. This change ensures the module is imported only when needed during runtime.

Author: TriPSs

src/pdf-to-png.ts

@@ -3,13 +3,13 @@
  */
 import { readFileSync } from 'node:fs'
 import { dirname, join } from 'node:path'
-import { getDocument } from 'pdfjs-dist/legacy/build/pdf.mjs'
 
 const PDFJS_DIR = join(dirname(require.resolve('pdfjs-dist')), '..')
 
 export async function pdfToPng(
   pdf: string | Buffer
 ): Promise<Buffer[]> {
+  const { getDocument } = await import('pdfjs-dist/legacy/build/pdf.mjs')
 
   // Load PDF
   const data = new Uint8Array(Buffer.isBuffer(pdf) ? pdf : readFileSync(pdf))