Updated the Chart.yaml file for the paperless-ngx Helm chart.
This change increments the chart version from 0.25.11 to 0.26.2 and
the app version from 2.20.1 to 2.20.2. These updates were necessary
to ensure users have access to the latest features and bug fixes
included in these versions. No breaking changes are introduced,
but users should review the release notes for each version for
any specific updates or changes in behavior.
