Added two notes

Author: ToriLindsay

src/content/docs/workers/runtime-apis/cache.mdx

@@ -109,6 +109,10 @@ The `stale-while-revalidate` and `stale-if-error` directives are not supported w
 
 :::
 
+:::note
+Do not use dynamic or invalid hostnames in cache requests. This can cause DNS cache failures and latency.
+:::
+
 #### Parameters
 
 
@@ -156,6 +160,10 @@ The `stale-while-revalidate` and `stale-if-error` directives are not supported w
 
 :::
 
+:::note
+Do not use dynamic or invalid hostnames in cache requests. This can cause DNS cache failures and latency.
+:::
+
 #### Parameters