Drop deprecated source from tweet.fields (#450)

* fix: drop deprecated `source` from tweet.fields (removed from X API v2)

* revert: restore openapi.json (auto-generated; source removal happens upstream)

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Co-authored-by: mintlify[bot] <109931778+mintlify[bot]@users.noreply.github.com>

Author: mintlify[bot]

x-api/posts/lookup/integrate.mdx

@@ -99,7 +99,6 @@ The X API v2 returns minimal data by default. Use `fields` and `expansions` to r
 | `context_annotations` | Topic/entity classifications |
 | `in_reply_to_user_id` | User being replied to |
 | `lang` | Detected language |
-| `source` | Posting client |
 | `possibly_sensitive` | Sensitive content flag |
 | `reply_settings` | Who can reply |
 </Accordion>