fix(index): prevent shifting on dashboard group hover

Add a transparent border to the default state of dashboard and dashboard
group elements to fix shifting on hover

Author: jbpratt

web/src/testgrid-index.ts

@@ -207,26 +207,26 @@ export class TestgridIndex extends LitElement {
     .dashboard {
       background-color: #9e60eb;
       color: #fff;
+      border: 2px solid transparent;
     }
 
     .dashboard-group {
       background-color: #707df1;
       color: #fff;
+      border: 2px solid transparent;
     }
 
     .dashboard-group:focus,
     .dashboard-group:hover {
       background-color: #fff;
       color: #707df1;
-      border-style: solid;
       border-color: #707df1;
     }
 
     .dashboard:hover,
     .dashboard:focus {
       background-color: #fff;
       color: #9e60eb;
-      border-style: solid;
       border-color: #9e60eb;
     }