doc: remove devpreview notice from hugepages docs

We have decided to move hugepages support out of developer preview,
despite missing support for memory ballooning.

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

docs/hugepages.md

@@ -1,10 +1,5 @@
 # Backing Guest Memory by Huge Pages
 
-> [!WARNING]
->
-> Support is currently in **developer preview**. See
-> [this section](RELEASE_POLICY.md#developer-preview-features) for more info.
-
 Firecracker supports backing the guest memory of a VM by 2MB hugetlbfs pages.
 This can be enabled by setting the `huge_pages` field of `PUT` or `PATCH`
 requests to the `/machine-config` endpoint to `2M`.