Error during destruction of the Editing-instance

[Snuffleupagus]

Attach (recommended) or Link to PDF file here: N/A

Configuration:

• Web browser and its version: N/A
• Operating system and its version: N/A
• PDF.js version: Any version after PR [Editor] Dispatch an event when some global states are changing (bug 1777695) #15130
• Is a browser extension: N/A

Steps to reproduce the problem:

1. Open the development viewer locally, after running gulp server, http://localhost:8888/web/viewer.html
2. Enable FreeText editing. (Note that Ink editing is similarly affected.)
3. Click on any page, and add a new comment (e.g. "Hello world").
4. Open the web-console, and run PDFViewerApplication.close().

What is the expected behavior? (add screenshot)
Closing works correctly.

What went wrong? (add screenshot)
An error is thrown:

Uncaught (in promise) TypeError: editor.destroy is not a function
    destroy http://localhost:8888/src/display/editor/tools.js:439
    setDocument http://localhost:8888/web/base_viewer.js:644
    close http://localhost:8888/web/app.js:866
    async* debugger eval code:1

Basically, the issue is that none of the AnnotationEditor-classes implement a destroy-method. The simplest solution would be to just remove this code:

pdf.js/src/display/editor/tools.js

Lines 438 to 440 in b0a3c9e

	for (const editor of this.#allEditors.values()) {
	editor.destroy();
	}

Another solution would be to actually implement destroy-functionality for the AnnotationEditor-classes, but I'm not sure if that's actually necessary here (given that we're tearing down the current Editing-instance)?

/cc @calixteman What solution is "correct" here? If it's the first one I could definitely submit a PR to fix it.

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

[calixteman]

It's a leftover: we just need to remove these 3 lines.