Update shelljs to 0.8.4

Summary:
Changelog: [Internal] - shelljs < 0.8.4 triggers warnings for node 14 and above.

See nodejs/node#32987 (comment)

Reviewed By: ShikaSD

Differential Revision: D33121070

fbshipit-source-id: 04d5e2c4295186fbad542bbc6085e491fc0d9d21

Author: Luna Wei

repo-config/package.json

@@ -45,7 +45,7 @@
     "react-native-codegen": "^0.0.12",
     "react-shallow-renderer": "16.14.1",
     "react-test-renderer": "17.0.2",
-    "shelljs": "^0.7.8",
+    "shelljs": "^0.8.4",
     "signedsource": "^1.0.0",
     "ws": "^6.1.4",
     "yargs": "^15.3.1"

yarn.lock

@@ -6611,10 +6611,10 @@ shell-utils@^1.0.9:
   dependencies:
     lodash "4.x.x"
 
-shelljs@^0.7.8:
-  version "0.7.8"
-  resolved "https://registry.yarnpkg.com/shelljs/-/shelljs-0.7.8.tgz#decbcf874b0d1e5fb72e14b164a9683048e9acb3"
-  integrity sha1-3svPh0sNHl+3LhSxZKloMEjprLM=
+shelljs@^0.8.4:
+  version "0.8.4"
+  resolved "https://registry.yarnpkg.com/shelljs/-/shelljs-0.8.4.tgz#de7684feeb767f8716b326078a8a00875890e3c2"
+  integrity sha512-7gk3UZ9kOfPLIAbslLzyWeGiEqx9e3rxwZM0KE6EL8GlGwjym9Mrlx5/p33bWTu9YG6vcS4MBxYZDHYr5lr8BQ==
   dependencies:
     glob "^7.0.0"
     interpret "^1.0.0"