docs: drop ferndef auth changes

Co-Authored-By: Devin Logan <devinannlogan@gmail.com>

Author: devin-ai-integration[bot]

fern/products/api-def/ferndef/auth.mdx

@@ -131,30 +131,6 @@ client = new Client({
 })
 ```
 
-### Omit username or password
-
-If your API only expects one half of a basic auth credential pair (for example, a token in the username and an empty password), set `omit: true` on the field you want to remove from the generated SDK:
-
-```yaml title="api.yml" {8}
-auth: Basic
-auth-schemes:
-  Basic:
-    scheme: basic
-    username:
-      name: apiToken
-    password:
-      omit: true
-```
-
-The omitted field is removed from the SDK's constructor entirely. Internally, an empty string is used to encode the `Authorization` header — omitting `password` produces `base64("apiToken:")`, and omitting `username` produces `base64(":password")`. If both fields are omitted, no `Authorization` header is sent.
-
-```ts index.ts
-// Only the non-omitted field is exposed
-const client = new Client({
-  apiToken: "ey34..."
-})
-```
-
 ## Custom header (e.g. API key)
 
 You can also create your own authentication scheme with customized headers.