fix: Templating of keywords

Author: sbernauer

template/deploy/helm/[[operator]]/Chart.yaml.j2

@@ -9,10 +9,7 @@ home: https://github.com/stackabletech/{[ operator.name }]
 sources:
  - https://github.com/stackabletech/{[ operator.name }]
 
-keywords:
-{[%- for keyword in operator.keywords %}]
- - {[ keyword }]
-{[%- endfor %}]
+keywords: {[ operator.keywords | tojson }]
 
 maintainers:
  - name: Stackable