fix: packages/babel-preset-react-app/package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-LODASH-15869625
- https://snyk.io/vuln/SNYK-JS-LODASH-15869619

Author: snyk-io[bot]

packages/babel-preset-react-app/package.json

@@ -21,7 +21,7 @@
     "test.js"
   ],
   "dependencies": {
-    "@babel/core": "7.12.3",
+    "@babel/core": "7.13.14",
     "@babel/plugin-proposal-class-properties": "7.12.1",
     "@babel/plugin-proposal-decorators": "7.12.1",
     "@babel/plugin-proposal-nullish-coalescing-operator": "7.12.1",