Drop abandoned add-on (Sosivio)

Sosivio seems to be abandoned, there's no Github activity and the
website is down [1][2].

The helm registry is also down[3], which is currently blocking the
Microk8s CI.

That being considered, we'll drop the Sosovio add-on.

[1] https://github.com/Sosivio
[2] https://docs.sosiv.io/
[3] https://helm.sosiv.io/

Author: petrutlucian94

addons.yaml

@@ -161,13 +161,6 @@ microk8s-addons:
         - amd64
         - arm64
 
-    - name: "sosivio"
-      description: "Kubernetes Predictive Troubleshooting, Observability, and Resource Optimization"
-      version: "1.7.1"
-      check_status: "deployment.apps/sosivio-dashboard"
-      supported_architectures:
-        - amd64
-
     - name: "kwasm"
       description: "WebAssembly support for WasmEdge (Docker Wasm) and Spin (Azure AKS WASI)"
       version: "0.2.0"