Chore: fix runaway test issue (#6460)

## Motivation for features / changes
In #6458 I fixed a couple of a tests which should have been failing but
were sporadically passing. In this PR I believe I have fixed the
underlying cause of the flakiness.
Thanks #6266 for pointing the way.

This broke nightly last night

https://github.com/tensorflow/tensorboard/actions/runs/5388986210/jobs/9782358616

Author: rileyajones

tensorboard/webapp/core/views/layout_test.ts

@@ -86,8 +86,6 @@ describe('layout test', () => {
       dispatchedActions.push(action);
     });
     store.overrideSelector(getSideBarWidthInPercent, 10);
-    // When the runs table is full screen the width is overridden to 100%.
-    store.overrideSelector(getRunsTableFullScreen, false);
   });
 
   afterEach(() => {

tensorboard/webapp/metrics/views/metrics_container_test.ts

@@ -40,6 +40,10 @@ describe('metrics view', () => {
     store = TestBed.inject<Store<State>>(Store) as MockStore<State>;
   });
 
+  afterEach(() => {
+    store.resetSelectors();
+  });
+
   it('renders', () => {
     store.overrideSelector(getEnableHparamsInTimeSeries, false);
     const fixture = TestBed.createComponent(MetricsDashboardContainer);

tensorboard/webapp/runs/views/runs_table/runs_data_table.ts

@@ -89,15 +89,15 @@ export class RunsDataTable {
   }
 
   getRunIds() {
-    return (this.data || []).map((row) => row.id);
+    return this.data.map((row) => row.id);
   }
 
   allRowsSelected() {
-    return (this.data || []).every((row) => row['selected']);
+    return this.data.every((row) => row['selected']);
   }
 
   someRowsSelected() {
-    return (this.data || []).some((row) => row['selected']);
+    return this.data.some((row) => row['selected']);
   }
 
   onFilterKeyUp(event: KeyboardEvent) {