chore: revert fs-extra to 7.x to fix incompatibilities with graceful-fs

See: jprichardson/node-fs-extra#687

packages/@vue/cli-service/package.json

@@ -49,7 +49,7 @@
     "dotenv": "^8.0.0",
     "dotenv-expand": "^5.1.0",
     "file-loader": "^3.0.1",
-    "fs-extra": "^8.0.1",
+    "fs-extra": "^7.0.1",
     "globby": "^9.2.0",
     "hash-sum": "^1.0.2",
     "html-webpack-plugin": "^3.2.0",

packages/@vue/cli-test-utils/package.json

@@ -23,7 +23,7 @@
   },
   "dependencies": {
     "execa": "^1.0.0",
-    "fs-extra": "^8.0.1",
+    "fs-extra": "^7.0.1",
     "json-server": "^0.14.0",
     "puppeteer": "^1.11.0",
     "strip-ansi": "^5.2.0"

packages/@vue/cli-ui/package.json

@@ -41,7 +41,7 @@
     "execa": "^1.0.0",
     "express-history-api-fallback": "^2.2.1",
     "fkill": "^6.1.0",
-    "fs-extra": "^8.0.1",
+    "fs-extra": "^7.0.1",
     "globby": "^9.2.0",
     "graphql": "^14.2.1",
     "graphql-subscriptions": "^1.1.0",

packages/@vue/cli/package.json

@@ -38,7 +38,7 @@
     "ejs": "^2.6.1",
     "envinfo": "^7.2.0",
     "execa": "^1.0.0",
-    "fs-extra": "^8.0.1",
+    "fs-extra": "^7.0.1",
     "globby": "^9.2.0",
     "import-global": "^0.1.0",
     "inquirer": "^6.3.1",

yarn.lock

@@ -7360,15 +7360,6 @@ fs-extra@^7.0.0, fs-extra@^7.0.1:
     jsonfile "^4.0.0"
     universalify "^0.1.0"
 
-fs-extra@^8.0.1:
-  version "8.0.1"
-  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-8.0.1.tgz#90294081f978b1f182f347a440a209154344285b"
-  integrity sha512-W+XLrggcDzlle47X/XnS7FXrXu9sDo+Ze9zpndeBxdgv88FHLm1HtmkhEwavruS6koanBjp098rUpHs65EmG7A==
-  dependencies:
-    graceful-fs "^4.1.2"
-    jsonfile "^4.0.0"
-    universalify "^0.1.0"
-
 fs-extra@~0.26.5:
   version "0.26.7"
   resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-0.26.7.tgz#9ae1fdd94897798edab76d0918cf42d0c3184fa9"