[workers-observability] update workers logs billing start date (#21140)

Co-authored-by: Rohin Lohe <[email protected]>

Author: rohinlohe

src/content/docs/workers/observability/logs/workers-logs.mdx

@@ -200,7 +200,7 @@ head_sampling_rate = 0.01 # 1% sampling rate
 ## Pricing
 
 :::note[Billing start date]
-Workers Logs billing will begin on November 1, 2024.
+Workers Logs billing will begin on April 21, 2025.
 :::
 <Render file="workers_logs_pricing" />