Referenced registries: '*' have not been configured in the root of dependabot.yml

[robvangeloven]

Describe the bug
Specifying registries as "" will give the error "Referenced registries: '' have not been configured in the root of dependabot.yml"

This worked in version 1.20.0

Possibly caused by change #781

To Reproduce
Using this dependabot.yml as config:

version: 2

registries:
  private:
    type: 'nuget-feed'
    url: '<private https feed>'
  public:
    type: 'nuget-feed'
    url: 'https://api.nuget.org/v3/index.json'

updates:
  - package-ecosystem: 'nuget'
    directory: '/Source'
    registries: "*"
    schedule:
      interval: 'daily'
    # Open PR against branch develop
    target-branch: 'develop'
    milestone: 12345

Expected behavior
According to the docs this should be a valid config: https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#registries

Extension (please complete the following information):

• Host: Azure DevOps
• Version 1.21.0

Server (please complete the following information):

• Region westeurope
• Version 1.21.0

[mburumaxwell]

Please search for existing issues before creating new ones.
See #813 and #823

[robvangeloven]

My bad! I searched, but not with the correct terms. Closing this one