#38666: Fix host list UI "jumping" bug (#39022)

<!-- Add the related story/sub-task/bug number, like Resolves #123, or
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**Related issue:** Resolves #38666 

# Checklist for submitter

If some of the following don't apply, delete the relevant line.

- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/guides/committing-changes.md#changes-files)
for more information.

## Testing

- [x] QA'd all new/changed functionality manually

changes/38666-hosts-ui-bug

@@ -0,0 +1 @@
+* Fixed a UI bug where the host list was being pushed down when viewing with a platform filter.

frontend/pages/hosts/ManageHostsPage/components/HostsFilterBlock/HostsFilterBlock.tsx

@@ -604,7 +604,10 @@ const HostsFilterBlock = ({
     );
   };
 
-  const showSelectedLabel = selectedLabel && selectedLabel.type !== "all";
+  const showSelectedLabel =
+    selectedLabel &&
+    selectedLabel.type !== "all" &&
+    selectedLabel.type !== "platform";
 
   if (
     showSelectedLabel ||