Remove white shadow in metrics charts

[fabiovincenzi]

Fixes #G-Research/fasttrackml#861.
Remove the white shadow around the active runs metrics as it significantly slowed down performance.

[jescalada]

There's a great improvement in performance when removing the drop-shadow! It causes a lot of lag because it creates a shadow by diffusing the "shape" of the div which is computationally expensive.

I also noticed a slight increase in performance using the built-in ease-in-out transition, rather than the cubic-bezier, but it might just be my imagination. May I ask how you managed to get 10000 active runs? I can only get so many runs locally until I running out of memory.

[fabiovincenzi]

There's a great improvement in performance when removing the drop-shadow! It causes a lot of lag because it creates a shadow by diffusing the "shape" of the div which is computationally expensive.

I also noticed a slight increase in performance using the built-in ease-in-out transition, rather than the cubic-bezier, but it might just be my imagination. May I ask how you managed to get 10000 active runs? I can only get so many runs locally until I running out of memory.

@jescalada They are actually 5000 active runs with 2 metrics per each