Remove a line that is not accurate to the current usages of GRIT
What does this MR do?
This MR removes a bullet point for "who uses GRIT"
Why was this MR needed?
As discussed in the Runners Platform sync, this bullet point about who uses GRIT is not currently accurate.
What's the best way to test this MR?
Review the docs
What are the relevant issue numbers?
N/A