Make downloadManager optional in JSDoc types

[wojtekmaj]

Reading from the source code:

pdf.js/src/display/annotation_layer.js

Line 2846 in 57d196e

this.downloadManager?.openOrDownloadData(

it appears to me it was not an intention to mark downloadManager as a required parameter in AnnotationLayerParameters:

pdf.js/src/display/annotation_layer.js

Line 63 in 57d196e

* @property {IDownloadManager} downloadManager

and AnnotationLayerBuilderOptions:

pdf.js/web/annotation_layer_builder.js

Line 40 in 57d196e

* @property {IDownloadManager} downloadManager

and it should be optional, similarly to accessibilityManager for example:

pdf.js/web/text_layer_builder.js

Line 30 in 57d196e

* @property {TextAccessibilityManager} [accessibilityManager]

Configuration:

• PDF.js version: 2.11.174
• Is a browser extension: no

What is the expected behavior? (add screenshot)

downloadManager to be optional

What went wrong? (add screenshot)

downloadManager marked as required

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):