Sponsorblock isn't applied in audio-only playback ('background' player)

[ghost]

Checklist

• I am able to reproduce the bug with the latest version.
• I am not able to reproduce the bug with the same version of upstream NewPipe.
• I made sure that there are no existing issues - open or closed - which I could contribute my information to.
• I have read the FAQ and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the bug report will be dismissed otherwise.
• This issue contains only one bug.
• I have read and understood the contribution guidelines.

Affected version

v0.25.1, potentially every version of the app

Steps to reproduce the bug

1. enable the Sponsorblock categories in the app settings
2. open a YT video containing Sponsorblock-recognized sponsorship (e.g. https://www.youtube.com/watch?v=k7wnNt65lcE)
3. play and inspect how the promotion segments are skipped
4. switch to the 'background' (audio-only) player and inspect how the promotion segments are not skipped

Expected behavior

The promotion portions present in the Sponsorblock database are skipped in identical fashion with both the video and 'background' player.

Affected Android/Custom ROM version

Android 13 / LineageOS 20

[Atemu]

Duplicate of #257.

[ghost]

Duplicate of #257.

Sorry, I searched for issues with audio in their title.