Deprecate authToken

## Problem
When using the `authToken` for Grafana Cloud, users encounter a confusing error message:

```
[ERROR] upload profile: failed to upload. server responded with statusCode: '401' and body: '{"status":"error","error":"authentication error: legacy auth cannot be upgraded because the host is not found"}'
```

## Solution
We should deprecate the use of `authToken` for authentication in Grafana Cloud.

Warn users if `authToken` is specified and the URL is not pointing to the OG Pyroscope Cloud.

Locate the Java integration's authToken configuration and authentication validation, then trace how the service URL is handled. Add a warning when authToken is used with a URL other than the OG Pyroscope Cloud, and confirm the warning addresses the confusing Grafana Cloud authentication case described in the issue.

Scritto dal modello di indicizzazione a partire dal testo della issue.