### Why are the changes needed?
The change fixes minor issue that resolves the following error:
```shell
../kyuubi/docs/contributing/doc/get_started.rst:78: ERROR: Content block expected for the "note" directive; none found. [docutils]
```
### How was this patch tested?
Built documentation locally and checked there are no difference and error message.
Before changes:
<img width="1214" alt="image" src="https://github.com/user-attachments/assets/f53398d8-b04a-4367-8040-3e6573cc54f2" />
After changes:
<img width="1197" alt="image" src="https://github.com/user-attachments/assets/3b08e1ee-11c2-4386-b178-35e33d6a56dc" />
### Was this patch authored or co-authored using generative AI tooling?
No
Closes#6977 from dnskr/remove-empty-note-block.
Closes#6977
942a2687e [dnskr] [DOC] Remove empty note block
Authored-by: dnskr <dnskrv88@gmail.com>
Signed-off-by: Kent Yao <yao@apache.org>
a3ccc4bc02