Review org-level budgets for Sentry

From some further investigation, it looks likely that we can reduce the number of error events being logged to the `dotcom-rendering` project. However, any reductions here will likely be swamped, for the time being, by events being logged in the `client-side-prod` project. The longer-term response to the quota issue should involve assessing whether we can reduce these events.

Given that the latter project is shared between a number of teams, we should coordinate on a solution.