Fix apostrophe and remove banner

src/content/docs/ssl/reference/migration-guides/lets-encrypt-chain.mdx

@@ -5,11 +5,8 @@ sidebar:
   order: 2
 head: []
 description: Review notes on the expiration of ISRG Root X1 cross-signed with
-  DST Root CA X3, and how it may affect Cloudflare customers that use Let’s
+  DST Root CA X3, and how it may affect Cloudflare customers that use Let's
   Encrypt.
-banner:
-    content: |
-        On September 9, 2024, Cloudflare will start rebundling all Let's Encrypt certificates using a new chain.
 ---
 
 import { Details } from "~/components";