[v9.3.x] Fix/60084/save and test (#62749)

Fix: Save and test error message does not persist across datasource instance settings anymore

(cherry picked from commit ce50168b70)

Co-authored-by: Timur Olzhabayev <timur.olzhabayev@grafana.com>

public/app/features/datasources/state/hooks.ts

@@ -22,6 +22,7 @@ import {
 } from './actions';
 import { DataSourcesRoutesContext } from './contexts';
 import { getDataSourceLoadingNav, buildNavModel, getDataSourceNav } from './navModel';
+import { initialDataSourceSettingsState } from './reducers';
 import { getDataSource, getDataSourceMeta } from './selectors';
 
 export const useInitDataSourceSettings = (uid: string) => {
@@ -33,7 +34,7 @@ export const useInitDataSourceSettings = (uid: string) => {
     return function cleanUp() {
       dispatch(
         cleanUpAction({
-          cleanupAction: (state) => state.dataSourceSettings,
+          cleanupAction: (state) => (state.dataSourceSettings = initialDataSourceSettingsState),
         })
       );
     };