fix: upgrade core-js from 3.38.1 to 3.39.0

Snyk has created this PR to upgrade core-js from 3.38.1 to 3.39.0.

See this package in npm:
core-js

See this project in Snyk:
https://app.snyk.io/org/travist-ulg/project/eeb4c0d9-fcd7-4f21-82a6-1086318fd04d?utm_source=github&utm_medium=referral&page=upgrade-pr

package.json

@@ -25,7 +25,7 @@
     "@formio/vpat": "github:formio/vpat#v2.5.4",
     "@uswds/uswds": "^3.8.2",
     "autocompleter": "^6.1.3",
-    "core-js": "^3.38.0",
+    "core-js": "^3.39.0",
     "eventemitter2": "^6.4.7",
     "flatpickr": "^4.6.13",
     "font-awesome": "^4.7.0",