[Excalidraw Extension] Blank custom editor in Gitpod Browser IDE

Bug description

The excalidraw custom editor does not display properly in gitpod.

However, it works fine in github.dev, github codespaces and vscode.

Steps to reproduce

• Open the excalidraw-vscode repository in gitpod
• Install the excalidraw extension
• Open the examples/text.excalidraw file

Workspace affected

excalidraw-excalidrawvs-bs2w57wmia6.ws-eu47.gitpod.io

Expected behavior

On github.dev, the test.excalidraw file is shown:

Example repository

https://github.com/excalidraw/excalidraw-vscode