chore: downgrade @openedx/brand-openedx to ^1.2.3 (#1347)

Reverts the v2 bump from openedx/public-engineering#505 while keeping
the existing @edx/brand npm alias. Refs openedx/public-engineering#508.

Author: arbrandes

package-lock.json

@@ -29,7 +29,7 @@
     "extends @edx/browserslist-config"
   ],
   "dependencies": {
-    "@edx/brand": "npm:@openedx/brand-openedx@^2.0.0",
+    "@edx/brand": "npm:@openedx/brand-openedx@^1.2.3",
     "@edx/frontend-component-footer": "^14.6.0",
     "@edx/frontend-component-header": "^8.2.1",
     "@edx/frontend-platform": "^8.7.0",