Add fixed viewport to vitest config

Author: acelaya

src/components/feedback/test/Popover-test.js

@@ -404,7 +404,7 @@ describe('Popover', () => {
       // Content is very big, so popover spans to the edge of the viewport and
       // grows further than the opposite side of the anchor element
       {
-        children: 'very long text'.repeat(4),
+        children: 'very long text'.repeat(8),
         align: 'left',
         getExpectedCoordinates: popoverDOMNode => {
           const popoverRect = popoverDOMNode.getBoundingClientRect();

vitest.config.js

@@ -14,6 +14,7 @@ export default defineConfig({
       headless: true,
       screenshotFailures: false,
       instances: [{ browser: 'chromium' }],
+      viewport: { width: 1024, height: 768 },
     },
 
     // CSS bundle relied upon by accessibility tests (eg. for color-contrast