Timeseries: Improve cursor Y sync behavior (#50740) (#50741)

(cherry picked from commit 4e4686001b)

Co-authored-by: Ryan McKinley <ryantxu@gmail.com>

packages/grafana-ui/src/components/GraphNG/__snapshots__/utils.test.ts.snap

@@ -77,13 +77,9 @@ Object {
         "pub": [Function],
       },
       "key": "__global_",
-      "match": Array [
-        [Function],
-        [Function],
-      ],
       "scales": Array [
         "x",
-        null,
+        "__fixed/na-na/na-na/auto/linear/na",
       ],
     },
   },

packages/grafana-ui/src/components/TimeSeries/utils.ts

@@ -465,10 +465,8 @@ export const preparePlotConfigBuilder: UPlotConfigPrepFn<{
           return true;
         },
       },
-      // ??? setSeries: syncMode === DashboardCursorSync.Tooltip,
-      //TODO: remove any once https://github.com/leeoniya/uPlot/pull/611 got merged or the typing is fixed
-      scales: [xScaleKey, null as any],
-      match: [() => true, () => true],
+      scales: [xScaleKey, yScaleKey],
+      // match: [() => true, (a, b) => a === b],
     };
   }