Repeated log spamming of "ImageName invalid" error message in the Agent

[jopemachine]

What Operating System(s) are you seeing this problem on?

Linux (x86-64)

Backend.AI version

main

Describe the bug

There are too many warning messages on the agent side indicating that the image names are in an incorrect format.

To Reproduce

Insert multiple records with incorrect image names into the image table.

Expected Behavior

Ensure that the warning message is displayed only once or, at the very least, is not displayed excessively.

Anything else?

No response