Remove the unused `capability` parameter from the `WorkerTransport.getPage` method
Remove the unused `capability` parameter from the `WorkerTransport.getPage` method

That parameter, originally named `promise`, has been unused for over five years; ever since commit https://github.com/mozilla/pdf.js/commit/f0687c4d50f4f674620b5cada5120421d2ba60c8 in PR 1531.

nawawi/pdf.js,macroplant/pdf.js,Snuffleupagus/pdf.js,Shoobx/pdf.js,macroplant/pdf.js,mainegreen/pdf.js,showpad/mozilla-pdf.js,timvandermeij/pdf.js,xavier114fch/pdf.js,caremerge/pdf.js,showpad/mozilla-pdf.js,adlerweb/pdf.js-Touch,xavier114fch/pdf.js,Rob--W/pdf.js,mozilla/pdf.js,Shoobx/pdf.js,nawawi/pdf.js,mozilla/pdf.js,timvandermeij/pdf.js,nawawi/pdf.js,Rob--W/pdf.js,Snuffleupagus/pdf.js,mukulmishra18/pdf.js,timvandermeij/pdf.js,mukulmishra18/pdf.js,adlerweb/pdf.js-Touch,macroplant/pdf.js,mainegreen/pdf.js,Snuffleupagus/pdf.js,showpad/mozilla-pdf.js,mozilla/pdf.js,Shoobx/pdf.js,caremerge/pdf.js