Update fs-extra requirement from ^7.0.0 to ^8.1.0

Updates the requirements on [fs-extra](https://github.com/jprichardson/node-fs-extra) to permit the latest version.
- [Release notes](https://github.com/jprichardson/node-fs-extra/releases)
- [Changelog](https://github.com/jprichardson/node-fs-extra/blob/master/CHANGELOG.md)
- [Commits](jprichardson/node-fs-extra@7.0.0...8.1.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

package.json

@@ -54,7 +54,7 @@
     "@iarna/toml": "^2.2.3",
     "appdirectory": "^0.1.0",
     "bluebird": "^3.0.6",
-    "fs-extra": "^7.0.0",
+    "fs-extra": "^8.1.0",
     "glob-all": "^3.1.0",
     "is-wsl": "^2.0.0",
     "jszip": "^3.1.0",