Auth: Enable case insensitive logins/emails by default (#84840)

* wip

* wip

* wip

* wip postgres tests

pkg/services/temp_user/tempuserimpl/store.go

@@ -106,11 +106,7 @@ func (ss *xormStore) GetTempUsersQuery(ctx context.Context, query *tempuser.GetT
 		}
 
 		if query.Email != "" {
-			if ss.cfg.CaseInsensitiveLogin {
-				rawSQL += ` AND LOWER(tu.email)=LOWER(?)`
-			} else {
-				rawSQL += ` AND tu.email=?`
-			}
+			rawSQL += ` AND LOWER(tu.email)=LOWER(?)`
 			params = append(params, query.Email)
 		}