Bump pdfjs-dist from 4.10.38 to 5.7.284 in /landing

Bumps [pdfjs-dist](https://github.com/mozilla/pdf.js) from 4.10.38 to 5.7.284.
- [Release notes](https://github.com/mozilla/pdf.js/releases)
- [Commits](mozilla/pdf.js@v4.10.38...v5.7.284)

---
updated-dependencies:
- dependency-name: pdfjs-dist
  dependency-version: 5.7.284
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

landing/package-lock.json

@@ -21,7 +21,7 @@
     "lucide-react": "^1.16.0",
     "marked": "^16.4.1",
     "pdf-lib": "^1.17.1",
-    "pdfjs-dist": "^4.7.76",
+    "pdfjs-dist": "^5.7.284",
     "react": "^19.2.6",
     "react-dom": "^19.2.6",
     "xlsx": "^0.18.5"