unified-storage: dont index -- Grafana -- datasource dashboard fields (#111774)

* unified-storage: dont index -- Grafana -- datasource dashboard fields

pkg/services/store/kind/dashboard/testdata/check-string-datasource-id-info.json

@@ -2,24 +2,12 @@
   "id": 250,
   "title": "fast streaming",
   "tags": null,
-  "datasource": [
-    {
-      "uid": "grafana",
-      "type": "datasource"
-    }
-  ],
   "panels": [
     {
       "id": 3,
       "title": "Panel Title",
       "type": "timeseries",
-      "pluginVersion": "7.5.0-pre",
-      "datasource": [
-        {
-          "uid": "grafana",
-          "type": "datasource"
-        }
-      ]
+      "pluginVersion": "7.5.0-pre"
     }
   ],
   "schemaVersion": 27,

pkg/services/store/kind/dashboard/testdata/special-datasource-types-info.json

@@ -3,10 +3,6 @@
   "title": "special ds",
   "tags": null,
   "datasource": [
-    {
-      "uid": "grafana",
-      "type": "datasource"
-    },
     {
       "uid": "dgd92lq7k",
       "type": "frser-sqlite-datasource"
@@ -22,10 +18,6 @@
       "title": "mixed ds with grafana ds",
       "type": "timeseries",
       "datasource": [
-        {
-          "uid": "grafana",
-          "type": "datasource"
-        },
         {
           "uid": "dgd92lq7k",
           "type": "frser-sqlite-datasource"
@@ -45,13 +37,7 @@
     {
       "id": 6,
       "title": "grafana ds",
-      "type": "timeseries",
-      "datasource": [
-        {
-          "uid": "grafana",
-          "type": "datasource"
-        }
-      ]
+      "type": "timeseries"
     },
     {
       "id": 2,