Gitea license

### 📋 Description

Badge idea: Gitea license (similar to github license badge)
Example:
`https://img.shields.io/gitea/license/username/repo?gitea_url=test`

### 🔗 Data

While gitea does support license type for repos the API does not return this value yet.
Requested in issue https://github.com/go-gitea/gitea/issues/12905
Recent work towards adding this in PR https://github.com/go-gitea/gitea/pull/24872

As suggested on discord, I think it's best to wait for it to get implemented. I will put a reminder and ping when its done.

### 🎤 Motivation

Opening after getting this request via discord (by @wesleybryie) so we don't lose track.
@CanisHelix seems to want to implement this when the API is implemented upstream

Start by checking whether the Gitea API now returns repository license data, using upstream issue 12905 and PR 24872 as the dependency. Once that data is available, implement the badge described by the example URL and verify that it renders the repository license correctly.

Written by the indexing model from the issue text.