[KYUUBI #7211] [DOC] Remove unsupported 'logo_only' and 'extra_navbar' theme options

### Why are the changes needed?
The PR fixes two `unsupported theme option` warnings that are printed during the documentation building:
```shell
preparing documents... WARNING: unsupported theme option 'logo_only' given
WARNING: unsupported theme option 'extra_navbar' given
```
Both options were deleted from [sphinx_book_theme](https://github.com/executablebooks/sphinx-book-theme).

### How was this patch tested?
Built documentation locally and checked there are no warning message anymore.

### Was this patch authored or co-authored using generative AI tooling?
No

Closes #7211 from dnskr/remove-unsupported-theme-options.

Closes #7211

800f9d9 [dnskr] [DOC] Remove unsupported 'logo_only' and 'extra_navbar' theme options

Authored-by: dnskr <[email protected]>
Signed-off-by: Cheng Pan <[email protected]>

Author: dnskr

docs/conf.py

@@ -108,13 +108,11 @@
     "use_fullscreen_button": True,
     "repository_branch": "master",
     "path_to_docs": "docs",
-    "logo_only": True,
     "home_page_in_toc": False,
     "show_navbar_depth": 1,
     "show_toc_level": 2,
     "announcement": "🦊 Welcome to Kyuubi’s online documentation ✨, v" + release,
     "toc_title": "",
-    "extra_navbar": "Version " + release,
 }
 
 html_logo = 'imgs/logo.png'