Update Workflows' pricing.mdx (#19321)

Removed duplicate page title, which caused 2 headers to display and both also listed in search results (duplicative).

Author: joslyn-cf

src/content/docs/workflows/reference/pricing.mdx

@@ -8,8 +8,6 @@ sidebar:
 
 import { Render } from "~/components"
 
-# Pricing
-
 :::note
 
 Workflows is included in both the Free and Paid [Workers plans](/workers/platform/pricing/#workers).