Widget: Misleading error message on "Error: User is not permitted to provision connections for GitLab"

## Steps to reproduce
1. Have someone else set up hookshot and the widget.
2. Open the widget.
3. Open the GitLab section.

## Expected
The widget tells you that you don't have the permissions to set up a GitLab connection.

## Actual
* The UI says `Error occured during widget load: There was an error fetching search results.`

* The JavaScript console knows about the actual issue:
```
Failed to get connection targets from query: Error: User is not permitted to provision connections for GitLab
Bt https://matrix.datanauten.de/hookshot/widgetapi/v1/static/assets/index.8ae1a773.js:5
request https://matrix.datanauten.de/hookshot/widgetapi/v1/static/assets/index.8ae1a773.js:5
index.8ae1a773.js:41:11707
```

Start in the widget's GitLab section and reproduce the failure when opening it with insufficient provisioning permissions. Trace the “Failed to get connection targets from query” path shown in the widget's compiled index.8ae1a773.js asset, then ensure the UI displays the permission error instead of the generic search-results message.

Written by the indexing model from the issue text.