Organization mapping for Okta doesn't update when set in config file

### What happened? When setting `org_mapping` under `[auth.okta]` in the grafana.ini file as in https://grafana.com/docs/grafana/latest/setup-grafana/configure-security/configure-authentication/okta/#org-roles-mapping-example, the "Organization mapping" setting when then viewed in the UI remains empty. <img width="626" height="177" alt="Image" src="https://github.com/user-attachments/assets/f5a323c0-9a6d-4510-8097-dd9543358af3" /> ### What did you expect to happen? The "Organization mapping" setting should be populated with whatever is set in grafana.ini ### Did this work before? Unsure, first time using the setting ### How do we reproduce it? 1. Populate grafana.ini with `org_mapping` under `[auth.okta]` as described in https://grafana.com/docs/grafana/latest/setup-grafana/configure-security/configure-authentication/okta/#org-roles-mapping-example 2. Go to <GRAFANA_URL>/admin/authentication/okta 3. Browse to "User mapping" section, look at "Organization mapping" setting, it remains blank ### Is the bug inside a dashboard panel? _No response_ ### Environment (with versions)? Grafana: 12.0.2 ### Grafana platform? A package manager (APT, YUM, BREW, etc.) ### Datasource(s)? _No response_