The last chart in the helm repo is 10 months old.
helm repo add redash https://getredash.github.io/contrib-helm-chart/
helm search repo redash --versions
NAME CHART VERSION APP VERSION DESCRIPTION
redash/redash 3.0.1 10.0.0.b50633 Redash is an open source tool built for teams t...
redash/redash 3.0.0 10.0.0.b50633 Redash is an open source tool built for teams t...
But the current Chart.yaml has this:
version: 3.0.1
appVersion: 10.1.0.b50633
Whenever you change something in the chart you need to update the 'version' field in the Chart.yaml so the GitHub Action / CircleCI, or whatever, will create a new chart.
The gh-pages branch has redash-3.0.1.tgz as "10 months old".