[Feature Request - Partner Center] WebExtension with `background.scripts` and `key`

Describe the bug

Microsoft Partner Center refuses to publish an extension with the background.scripts and key property in manifest V3.

I tried to publish my Cast Kodi extension which has two backgrounds specified in the manifest:

{
  "manifest_version": 3,
  "name": "Cast Kodi",
  "...": "...",
  "background": {
    "service_worker": "background.js",
    "scripts": ["background.js"],
    "type": "module"
  },
  "...": "...",
  "key": "MIIBIjANBg..."
}

Thanks to the Proposal: declaring background scripts in a neutral way w3c/webextensions#282 issue, I can use the same manifest for Chromium and Firefox.

• Firefox Browser Add-ons accepts manifest with background.service_worker and key.
• Chrome Web Store accepts manifest with background.scripts.

To Reproduce
Steps to reproduce the behavior:

1. Go to Microsoft Partner Center > Edge
2. Publish an extension with the background.scripts and key property in manifest V3.
3. See error

The following checks failed:

• Package acceptance validation error: The background.scripts field cannot be used with manifest version 3. Use the background.service_worker field instead. Error code: background: { "service_worker": "background.js", "scripts": [ "background.js" ], "type": "module" } Line: 30 Column: 17
• Package acceptance validation error: The manifest shouldn't contain the key field.

Expected behavior

Microsoft Partner Center accepts extension with the background.scripts and key property in manifest V3.

Desktop (please complete the following information):

• OS: Ubuntu 22.04.3 LTS
• Browser: Firefox
• Version: 122.0.1

Additional context

• https://github.com/w3c/webextensions/issues/282
• https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/background#browser_support
• https://issues.chromium.org/issues/40257904 Move from a hard-error to warning when loading extensions with the background.scripts key present

Related issues

• https://github.com/microsoft/MicrosoftEdge-Extensions/issues/165
• https://github.com/microsoft/MicrosoftEdge-Extensions/issues/172