Update custom-superchain-erc20.mdx

Author: qbzzt

pages/stack/interop/tutorials/custom-superchain-erc20.mdx

@@ -8,7 +8,7 @@ import { Callout } from 'nextra/components'
 import { Steps } from 'nextra/components'
 
 <Callout>
-  The SuperchainERC20 standard is ready for production use with active Mainnet deployments.
+  The SuperchainERC20 standard is ready for production deployments.
   Please note that the OP Stack interoperability upgrade, required for crosschain messaging, is currently still in active development.
 </Callout>