Bump to suggested 9.0.0 chart version

Co-authored-by: Pierluigi Lenoci <pierluigi.lenoci@sap.com>

Author: FieteO

helm/oauth2-proxy/Chart.yaml

@@ -1,5 +1,5 @@
 name: oauth2-proxy
-version: 8.4.0
+version: 9.0.0
 apiVersion: v2
 appVersion: 7.13.0
 home: https://oauth2-proxy.github.io/oauth2-proxy/