Update pdfjs-dist dependency to patch vulnerability

From `npm audit`:

```
pdfjs-dist  <=4.1.392
Severity: high
PDF.js vulnerable to arbitrary JavaScript execution upon opening a malicious PDF - https://github.com/advisories/GHSA-wgrm-67xf-hhpq
No fix available
node_modules/pdfjs-dist
  pdfvuer  *
  Depends on vulnerable versions of pdfjs-dist
  node_modules/pdfvuer
```