Merge branch 'update-gitaly-cluster-doc-grafana-password' into 'master'

Remove unused GRAFANA_PASSWORD secret in Gitaly Cluster docs

See merge request gitlab-org/gitlab!35812

doc/administration/gitaly/praefect.md

@@ -131,8 +131,6 @@ with secure tokens as you complete the setup process.
    Praefect cluster directly; that could lead to data loss.
 1. `PRAEFECT_SQL_PASSWORD`: this password is used by Praefect to connect to
    PostgreSQL.
-1. `GRAFANA_PASSWORD`: this password is used to access the `admin`
-   account in the Grafana dashboards.
 
 We will note in the instructions below where these secrets are required.