Jellyfin Docker's UI disables the ffmpeg path field

[nb-programmer]

Describe The Bug
When Docker version of Jellyfin is used, the "FFmpeg path" field (inside Dashboard / Playback / Transcoding page) cannot be altered from the default /usr/lib/jellyfin-ffmpeg/ffmpeg value. You might think, why this value might need to be changed since it is in a docker container, but you can use Docker volumes to mount a custom ffmpeg and use that (eg. rffmpeg or something else).
I see no way of enabling the field. The field is editable in the package version of Jellyfin.

Note that this issue is not limited to the webui but all the frontends (Android, etc.). Let me know if this issue needs to be moved somewhere else.

Steps To Reproduce

Using docker compose (following these instructions):

1. docker-compose.yml:

services:
  jellyfin:
    image: jellyfin/jellyfin

ports, volumes, etc...

2. docker compose up -d to start jellyfin
3. Go to Dashboard, inside Playback under Transcoding.
4. Scroll down to 'FFmpeg path'
5. Try to edit the field -> non editable

Expected Behavior

The 'FFmpeg path' field should be editable within Docker Jellyfin so that a custom FFMpeg from mounted volume can be used.

Logs

N/A

Screenshots

Dashboard / Playback / Transcoding page:

System (please complete the following information):

• Platform: Arch Linux 6.12.9-arch1-1 [but running as a Docker container]
• Browser: Chrome
• Jellyfin Version: 10.10.4 [Docker]

Additional Context

Behavior present in Jellyfin-web and Android (not tested on other platforms, but likely present).