Floor is slightly damaged by water – How to proceed?

Hi there,

I am leaving my current apartment at the end of the month and just noticed a water damage on my floor while moving the bad. I am not sure how to proceed here, is this type of water damage considered as wear and tear and should I just inform the landlord about it or should I try to fix it to avoid reduction of my deposit?

Floor is still flat so it looks like the damage is just a glue that came up to the surface. If I can somehow clean, do you have any recommendations on how to do it?

All three pictures are of the same spot, just each picture shows different angle.

Many thanks in advance!