Update setup-lab.sh

Added the following:

```
git config --global --add safe.directory /app
```

To make git stop complain about unsafe folders

Author: rofrano

.devcontainer/scripts/setup-lab.sh

@@ -2,6 +2,11 @@
 echo "Setting up Docker lab environment..."
 docker pull quay.io/rofrano/python:3.11-slim
 # docker run -d --name postgresql --restart always -p 5432:5432 -v postgres:/var/lib/postgresql/data postgres:alpine
+
 echo Setting up registry.local...
 sudo bash -c "echo '127.0.0.1    cluster-registry' >> /etc/hosts"
-echo "Setup complete"
+
+echo "Making git stop complaining about unsafe folders"
+git config --global --add safe.directory /app
+
+echo "Setup complete"