Removes Zeppelin code and docs (#1296)

* Update admin:admin reference

Signed-off-by: Derek Ho <[email protected]>

* Remove zeppelin code and docs

Signed-off-by: Derek Ho <[email protected]>

* Remove unecessary files

Signed-off-by: Derek Ho <[email protected]>

* Remove unnecessary constant

Signed-off-by: Derek Ho <[email protected]>

* Remove file

Signed-off-by: Derek Ho <[email protected]>

---------

Signed-off-by: Derek Ho <[email protected]>
(cherry picked from commit c241368)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]

common/constants/notebooks.ts

@@ -4,7 +4,6 @@
  */
 
 export const NOTEBOOKS_API_PREFIX = '/api/observability/notebooks';
-export const NOTEBOOKS_SELECTED_BACKEND: 'ZEPPELIN' | 'DEFAULT' = 'DEFAULT';
 export const NOTEBOOKS_FETCH_SIZE = 1000;
 export const CREATE_NOTE_MESSAGE = 'Enter a name to describe the purpose of this notebook.';
 export const NOTEBOOKS_DOCUMENTATION_URL =