Clarify license 澄清许可证

### Please make sure of the following things

- [X] I have read the [documentation](https://alist.nn.ci).
- [X] I'm sure there are no duplicate issues or discussions.
- [X] I'm sure this feature is not implemented.
- [X] I'm sure it's a reasonable and popular requirement.

### Description of the feature / 需求描述

Could you clarify whether by AGPLv3 you mean AGPL-3.0-only or AGPL-3.0-or-later?
请明确Alist使用的许可证为AGPL-3.0-only还是AGPL-3.0-or-later
https://gnu.org/licenses/identify-licenses-clearly.html.

### Suggested solution / 实现思路

_No response_

### Additional context / 附件

_No response_