entry.noworker doesn't work because of pdfjs-dist update

[Kerumen]

Since the version v2.0.310, the file pdf.combined.js in not present in the build anymore. Hence, the entry.noworker doesn't work.

They removed this entry in this PR.
I don't understand why but as a temporary solution to get this lib working you can pin the dependency of pdfjs-dist to 2.0.305.

[wojtekmaj]

[x] Fix on 3.x branch
[x] Cherry pick to 2.x branch
[x] Automatic testing
[x] Manual sanity checks
[x] Release 2.5.3 hotfix
[x] Release 3.0.0-alpha.4 hotfix

[Kerumen]

@wojtekmaj I'm installing this version in my project, will keep you updated.

[Kerumen]

@wojtekmaj It works fine! Thanks for the quick publish :)