Fix misleading cacheByDefault documentation (#4338)

Author: fredericDelaporte

docs/docs/api/Dispatcher.md

@@ -1103,7 +1103,7 @@ The `cache` interceptor implements client-side response caching as described in
 
 - `store` - The [`CacheStore`](/docs/docs/api/CacheStore.md) to store and retrieve responses from. Default is [`MemoryCacheStore`](/docs/docs/api/CacheStore.md#memorycachestore).
 - `methods` - The [**safe** HTTP methods](https://www.rfc-editor.org/rfc/rfc9110#section-9.2.1) to cache the response of.
-- `cacheByDefault` - The default expiration time to cache responses by if they don't have an explicit expiration. If this isn't present, responses without explicit expiration will not be cached. Default `undefined`.
+- `cacheByDefault` - The default expiration time to cache responses by if they don't have an explicit expiration and cannot have an heuristic expiry computed. If this isn't present, responses neither with an explicit expiration nor heuristically cacheable will not be cached. Default `undefined`.
 - `type` - The [type of cache](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Caching#types_of_caches) for Undici to act as. Can be `shared` or `private`. Default `shared`. `private` implies privately cacheable responses will be cached and potentially shared with other users of your application.
 
 ## Instance Events