[BUG] Notebook not isolated according to workspace

[yubonluo]

What is the bug?
When workspace enabled and accessing the Notebooks page, the notebook saved object is not isolated according to the workspace and displays data that does not belong to that workspace.

How can one reproduce the bug?
Steps to reproduce the behavior:
config:

workspace.enabled: true 
savedObjects.permission.enabled: true
opensearchDashboards.dashboardAdmin.users: ["admin"]

uiSettings:
   overrides:
     "home:useNewHomePage": true

1. Create two workspaces (ws1 and ws2).
2. Create a notebook test notebook in ws1.
3. Navigate to ws2 and go to Notebooks page
4. See the test notebook in the page.

What is the expected behavior?
When accessing notebook page, only the notebook belonging to the workspace should be displayed.

What is your host/environment?

• OS: [e.g. iOS]
• Version [e.g. 22]
• Plugins

Do you have any screenshots?

Do you have any additional context?
When call http://localhost:5601/w/dODCAo/api/observability/notebooks/savedNotebook/ will redirect to http://localhost:5601/api/observability/notebooks/savedNotebook/ which resulting in the lack of workspace information.
One solution is to remove the last / in https://github.com/opensearch-project/dashboards-observability/blob/main/public/components/notebooks/components/main.tsx#L111