fix(deps): update dependency netlify-cms-ui-default to ^2.15.4

Author: renovate-bot

package.json

@@ -33,7 +33,7 @@
   "dependencies": {
     "@emotion/core": "^10.0.35",
     "@emotion/styled": "^10.0.27",
-    "netlify-cms-ui-default": "^2.15.3",
+    "netlify-cms-ui-default": "^2.15.4",
     "react": "^16.8.4",
     "react-dom": "^16.8.4",
     "react-select": "^3.1.0",

yarn.lock

@@ -5594,10 +5594,10 @@ neo-async@^2.6.2:
   resolved "https://registry.yarnpkg.com/neo-async/-/neo-async-2.6.2.tgz#b4aafb93e3aeb2d8174ca53cf163ab7d7308305f"
   integrity sha512-Yd3UES5mWCSqR+qNT93S3UoYUkqAZ9lLg8a7g9rimsWmYGK8cVToA4/sF3RrshdyV3sAGMXVUmpMYOw+dLpOuw==
 
-netlify-cms-ui-default@^2.15.3:
-  version "2.15.3"
-  resolved "https://registry.yarnpkg.com/netlify-cms-ui-default/-/netlify-cms-ui-default-2.15.3.tgz#d40a83cabcd956515dfee0c92f828fb4d2c64d75"
-  integrity sha512-wxO//LOtX141lWbl2o1tS8ymSEJ9clmv8a+z3COKw2ksv65kTXi0pfnRbJ9UbgEsfPxvUIF7UKonQM74cupW/g==
+netlify-cms-ui-default@^2.15.4:
+  version "2.15.4"
+  resolved "https://registry.yarnpkg.com/netlify-cms-ui-default/-/netlify-cms-ui-default-2.15.4.tgz#40c50010a94718d87969258f2249c0c1ce749c82"
+  integrity sha512-GckgSG8NrzmV/0BxJbqptpykRs7ZBWRmaydLR1j18XnLwe/ZWDEnibyHbP7fLCQuPL5SjX8e/1yZ2tHTvtML4w==
   dependencies:
     react-aria-menubutton "^7.0.0"
     react-toggled "^1.1.2"