Use an ES5-compatible or legacy version of PDF.js

Since 10.10-HF37 (see ELEMENTS-1248 ), some old browsers display:

 PDF.js v2.6.347 (identifiant de compilation : 3be9c65f0)

Message: The browser/environment lacks native support for critical functionnality used by the PDF.js library (e.g. 'ReadableStream' and/or 'Promise.allSettled'); please use an ES5-compatible build instead)

One can find in https://github.com/mozilla/pdf.js/issues/12490 that PDF.js releases have changed names and compliance expectations:

From version 2.4.456 on we produce a non-translated/non-polyfilled build for modern browsers by default. However, we also provide the translated/polyfilled build for older browsers in a separate bundle (with the -es5-dist.zip suffix).

Looking in https://github.com/mozilla/pdf.js/releases , one can find there exists distributions of PDF.js with names
es5 distributions names in v2.6 and v2.7 of PDF.js
legacy distributions names in v2.8 and v2.9 of PDF.js

It is requested that the PDF.js library shipped with Nuxeo remains compatible with fossile browsers which were compatible prior to Nuxeo 10.10-HF37, thus it is requested that an ES5-compliant distribution of PDF.js be shipped with Nuxeo

As ELEMENTS-1248 was also fixed in WebUI 3.0.2, the same concern applies to an LTS 2021 compliant version of WebUI.