[BUG][ui] last row in spans and traces table is partially obstructed

[axiomofjoy]

While testing out pagination, I've noticed that the last row in the traces and spans table tends to be partially obstructed. To reproduce, work on the llama-index trace fixture and scroll with pagination to the bottom of the page until the spans run out. The problem gets worse as the aspect ratio of the browser widens. When working on a wide monitor, the bottom row becomes nearly invisible.