Update pricing.mdx

billing starts today, so removing wording saying when billing starts

Author: kathayl

src/content/docs/browser-rendering/platform/pricing.mdx

@@ -6,8 +6,6 @@ sidebar:
 ---
 import { Details } from "~/components"
 
-Browser Rendering is currently available at no cost up to the [limits](/browser-rendering/platform/limits/) specified, with billing beginning on August 20, 2025.
-
 There are two ways to use Browser Rendering. Depending on the method you use, here is how billing works:
 - [**REST API**](/browser-rendering/rest-api/): Charged for **Duration** only ($/browser hour)
 - [**Workers Bindings**](/browser-rendering/workers-bindings/): Charged for both **Duration** and **Concurrency** ($/browser hour and # of concurrent browsers)