I created a GitHub Action to upload an Anki add-on to AnkiWeb. It supports multiple Anki version branches and description file.
More information about the features and documentation can be found in the GitHub repository:
AnkiWeb’s Terms and Conditions don’t currently permit third-party API access. We’re planning to add public APIs in the future: API for uploading add-ons to Ankiweb · Issue #4869 · ankitects/anki · GitHub