Repository: yt-dlp
Issue: [Boosty] Support audio-only content
Labels: site-enhancement,triage

### DO NOT REMOVE OR SKIP THE ISSUE TEMPLATE

- [X] I understand that I will be **blocked** if I *intentionally* remove or skip any mandatory\* field

### Checklist

- [X] I'm requesting a site-specific feature
- [X] I've verified that I have **updated yt-dlp to nightly or master** ([update instructions](https://github.com/yt-dlp/yt-dlp#update-channels))
- [X] I've checked that all provided URLs are playable in a browser with the same IP and same login details
- [X] I've searched [known issues](https://github.com/yt-dlp/yt-dlp/issues/3766) and the [bugtracker](https://github.com/yt-dlp/yt-dlp/issues?q=) for similar issues **including closed ones**. DO NOT post duplicates
- [X] I've read the [guidelines for opening an issue](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#opening-an-issue)
- [ ] I've read about [sharing account credentials](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#are-you-willing-to-share-account-details-if-needed) and I'm willing to share it if required

### Region

Europe

### Example URLs

https://boosty.to/myrngwaur/posts/92f1592c-9fc5-4389-a45e-7e798e4b6d0e

### Provide a description that is worded well enough to be understood

Current extractor implementation only supports Boosty content of type `video` and `video_ok`.  The example page includes only an audio file and yt-dlp errors out with `ERROR: [Boosty] No videos found`.

The file in question has the following format in API output:

```json
{
  "showViewsCounter": false,
  "timeCode": 0,
  "id": "eebc5a6a-ea54-4193-826a-0725a8a0c380",
  "size": 43397364,
  "uploadStatus": "",
  "title": "История и источники_ истина где-то рядом.mp4",
  "url": "https://cdn.boosty.to/audio/eebc5a6a-ea54-4193-826a-0725a8a0c380",
  "album": "",
  "complete": true,
  "artist": "",
  "type": "audio_file",
  "viewsCounter": 19,
  "isMigrated": true,
  "duration": 3565,
  "track": ""
}
```

The URL is not directly downloadable without some request-signing magic though.

### Provide verbose output that clearly demonstrates the problem

- [X] Run **your** yt-dlp command with **-vU** flag added (`yt-dlp -vU <your command line>`)
- [ ] If using API, add `'verbose': True` to `YoutubeDL` params instead
- [X] Copy the WHOLE output (starting with `[debug] Command-line config`) and insert it below

### Complete Verbose Output

```shell
[debug] Command-line config: ['-vU', '--extract-audio', '--audio-format', 'm4a', '--embed-metadata', '--embed-thumbnail', '--cookies', 'boostie.cookie', 'https://boosty.to/myrngwaur/posts/92f1592c-9fc5-4389-a45e-7e798e4b6d0e']
[debug] Encodings: locale UTF-8, fs utf-8, pref UTF-8, out utf-8, error utf-8, screen utf-8
[debug] yt-dlp version stable@2024.10.22 from yt-dlp/yt-dlp [67adeb7ba] (zip)
[debug] Python 3.12.7 (CPython aarch64 64bit) - Linux-6.10.12-orbstack-00282-gd1783374c25e-aarch64-with (OpenSSL 3.3.2 3 Sep 2024)
[debug] exe versions: ffmpeg 6.1.1 (setts), ffprobe 6.1.1
[debug] Optional libraries: mutagen-1.47.0, sqlite3-3.45.3
[debug] Proxy map: {}
[debug] Request Handlers: urllib
[debug] Loaded 1839 extractors
[debug] Fetching release info: https://api.github.com/repos/yt-dlp/yt-dlp/releases/latest
Latest version: stable@2024.10.22 from yt-dlp/yt-dlp
yt-dlp is up to date (stable@2024.10.22 from yt-dlp/yt-dlp)
[Boosty] Extracting URL: https://boosty.to/myrngwaur/posts/92f1592c-9fc5-4389-a45e-7e798e4b6d0e
[Boosty] 92f1592c-9fc5-4389-a45e-7e798e4b6d0e: Downloading post data
ERROR: [Boosty] No videos found
  File "/usr/local/bin/yt-dlp/yt_dlp/extractor/common.py", line 741, in extract
    ie_result = self._real_extract(url)
                ^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/bin/yt-dlp/yt_dlp/extractor/boosty.py", line 222, in _real_extract
    raise ExtractorError('No videos found', expected=True)
```