[Bug] Peertube feed shows preview and multiple sources

### Describe the bug

When subscribing to a RSS Peertube channel, for each item you get video previews (not needed) and multiple videos if the video has multiple sources.

### To Reproduce

This is a video with the issue https://video.linux.it/w/27cWiLyWTR3QiZirueXDPu
this is how it is rendered

This is the RSS feed https://video.linux.it/feeds/videos.xml?videoChannelId=138

### Expected behavior

_No response_

### FreshRSS version

1.28.0

### System information

- Database version: [e.g. SQLite, PostgreSQL 17]
- PHP version: [e.g. PHP 8.2]
- Installation type: [e.g. Docker, Docker image source, git, Yunohost]
- Web server type: [e.g. Apache, nginx]
- Device: [e.g. iPhone13]
- OS: [e.g. Ubuntu 24.04, Win11, MacOS14]
- Browser: [e.g. Firefox 134]

### Additional context

_No response_