Add breakpoints to the Mantine theme overrides (#40903)

frontend/src/metabase/ui/theme.ts

@@ -39,6 +39,13 @@ import {
 import { getThemeColors } from "./utils/colors";
 
 export const getThemeOverrides = (): MantineThemeOverride => ({
+  breakpoints: {
+    xs: "23em",
+    sm: "40em",
+    md: "60em",
+    lg: "80em",
+    xl: "120em",
+  },
   colors: getThemeColors(),
   primaryColor: "brand",
   primaryShade: 0,