Bump @babel/plugin-proposal-nullish-coalescing-operator

Bumps [@babel/plugin-proposal-nullish-coalescing-operator](https://github.com/babel/babel) from 7.4.4 to 7.8.3.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/master/CHANGELOG.md)
- [Commits](babel/babel@v7.4.4...v7.8.3)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Author: dependabot-preview[bot]

package-lock.json

@@ -61,7 +61,7 @@
     "@babel/plugin-proposal-function-sent": "^7.0.0",
     "@babel/plugin-proposal-json-strings": "^7.8.3",
     "@babel/plugin-proposal-logical-assignment-operators": "^7.0.0",
-    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.0.0",
+    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.8.3",
     "@babel/plugin-proposal-numeric-separator": "^7.8.3",
     "@babel/plugin-proposal-optional-chaining": "^7.7.5",
     "@babel/plugin-proposal-pipeline-operator": "^7.0.0",