[Bug] Editor throws error on dispose after upgrade from 0.51 to 0.52

[vadimpopa]

Reproducible in vscode.dev or in VS Code Desktop?

• Not reproducible in vscode.dev or VS Code Desktop

Reproducible in the monaco editor playground?

• Not reproducible in the monaco editor playground

Monaco Editor Playground Link

No response

Monaco Editor Playground Code

No response

Reproduction Steps

No response

Actual (Problematic) Behavior

After upgrading from 0.51 to 0.52 we get an error when editor.dispose() is called. I also noticed that when I remove the onDidChangeModelContent listener we don't get the error. It seems that there is some async in here because if I dispose editor in a timeout then I don't get the error as well.
I tried our code in playground, and we couldn't reproduce which is weird too, as we don't have anything uncommon.

We dispose everything as following:

	if (this.modelChangeDisposable) {
            this.modelChangeDisposable.dispose(); // what editorInstance.onDidChangeModelContent returns.
         }
         editor.getModel().dispose();
	editor.dispose();

Expected Behavior

No response

Additional Context

No response

[inad9300]

I started seeing the same problem after upgrading to 0.52.2. Here is my stack trace, in case it helps:

async.js:219 Uncaught (in promise) Canceled: Canceled
    at Delayer.cancel (https://localhost:5000/static/js/vendors-node_modules_monaco-editor_esm_vs_editor_editor_main_js.chunk.js:25592:115)
    at Delayer.dispose (https://localhost:5000/static/js/vendors-node_modules_monaco-editor_esm_vs_editor_editor_main_js.chunk.js:25602:10)
    at dispose (https://localhost:5000/static/js/vendors-node_modules_monaco-editor_esm_vs_editor_editor_main_js.chunk.js:34334:13)
    at DisposableStore.clear (https://localhost:5000/static/js/vendors-node_modules_monaco-editor_esm_vs_editor_editor_main_js.chunk.js:34417:7)
    at DisposableStore.dispose (https://localhost:5000/static/js/vendors-node_modules_monaco-editor_esm_vs_editor_editor_main_js.chunk.js:34401:10)
    at WordHighlighter.dispose (https://localhost:5000/static/js/vendors-node_modules_monaco-editor_esm_vs_editor_editor_main_js.chunk.js:177966:19)
    at WordHighlighterContribution.dispose (https://localhost:5000/static/js/vendors-node_modules_monaco-editor_esm_vs_editor_editor_main_js.chunk.js:178017:29)
    at dispose (https://localhost:5000/static/js/vendors-node_modules_monaco-editor_esm_vs_editor_editor_main_js.chunk.js:34334:13)
    at DisposableMap.clearAndDisposeAll (https://localhost:5000/static/js/vendors-node_modules_monaco-editor_esm_vs_editor_editor_main_js.chunk.js:34576:7)
    at DisposableMap.dispose (https://localhost:5000/static/js/vendors-node_modules_monaco-editor_esm_vs_editor_editor_main_js.chunk.js:34566:10)