No validation errors when updating a media item with an empty file

[nhudinh0309]

Which Umbraco version are you using?

16.3.0-rc

Bug summary

Updating a media item with an empty file wasn't allowed in V13, but it is possible now.

Umbraco.-.Google.Chrome.2025-08-29.15-19-43.mp4

Specifics

No response

Steps to reproduce

1. Go to a media item
2. Remove media file and click 'Save'

Expected result / actual result

Expected result
A validation error should be displayed, the same as in v13.

Actual result
The media item can be saved without any error.

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This item has been added to our backlog AB#56358

[NillasKA]

Fixed by #20101 for 16.3