fix: Update to MorphoCloud/MorphoCloudWorkflow@6b8b2e1

List of MorphoCloudWorkflow changes:

```
$ git shortlog f9e9dda..6b8b2e1 --no-merges
Jean-Christophe Fillion-Robin (1):
      fix(cloud-config): Update to MorphoCloud/exosphere@5683d349b
```

See MorphoCloud/MorphoCloudWorkflow@f9e9dda...6b8b2e1

cloud-config

@@ -55,7 +55,7 @@ retry git clone \
   "https://github.com/MorphoCloud/exosphere.git" \
   /opt/instance-config-mgt
 
-exosphere_sha="61891a755ee0a4f9d15b586d60477814885656fc" # morpho-cloud-portal-2025.01.29-5f7a4c38
+exosphere_sha="5683d349b2bec4c403e418c44d2bac3326a3fce8" # morpho-cloud-portal-2025.01.29-5f7a4c38
 (cd /opt/instance-config-mgt && git reset --hard $exosphere_sha)
 
 ansible-playbook \