fix(base-select): [base-select] modify test cases

Author: MomoPoppy

examples/sites/demos/pc/app/base-select/popup-style-position.spec.ts

@@ -11,5 +11,5 @@ test('popup-style-position', async ({ page }) => {
   await select.click()
   await expect(dropdown).toHaveCount(1)
   await expect(dropdown).toHaveClass(/drop/)
-  await expect(dropdown).toHaveCSS('background-color', 'rgb(213, 232, 255)')
+  await expect(dropdown).toHaveCSS('background-color', 'rgb(255,255, 255)')
 })