DEV: this class is no longer present in chart js 3.x (#132)

test/javascripts/acceptance/run-query-test.js.es6

@@ -186,9 +186,6 @@ acceptance("Data Explorer Plugin | Run Query", function (needs) {
 
     await click("div.result-info button:nth-child(3)");
 
-    assert.ok(
-      exists("canvas.chartjs-render-monitor"),
-      "the chart was rendered"
-    );
+    assert.ok(exists("canvas"), "the chart was rendered");
   });
 });

test/javascripts/integration/components/data-explorer-bar-chart-test.js.es6

@@ -20,10 +20,6 @@ discourseModule(
 
       async test(assert) {
         assert.ok(exists("canvas"), "it renders a canvas");
-        assert.ok(
-          exists("canvas.chartjs-render-monitor"),
-          "it initializes chart.js "
-        );
       },
     });
   }

test/javascripts/integration/components/query-result-test.js.es6

@@ -139,10 +139,7 @@ discourseModule(
           I18n.t("explorer.show_table"),
           "the chart button was changed to the table button"
         );
-        assert.ok(
-          exists("canvas.chartjs-render-monitor"),
-          "the chart was rendered"
-        );
+        assert.ok(exists("canvas"), "the chart was rendered");
 
         await click("div.result-info button:nth-child(3)");
         assert.equal(