monitoring: difficult to understand 7d provisioning panel

Created by: bobheadxi

at the default 6h window:

at 7d:

I think the max over 7 days causes some funny business here (not sure if removed instances are being removed from the panel correctly, since there's a lot of overlapping going on) and at smaller windows it almost always just looks like a mess of straight lines 🤔

cc @slimsag

related: https://github.com/sourcegraph/sourcegraph/issues/12032