Merge branch '39096-upgrade-vuex' into 'master'

Update Vuex version

Closes #39096

See merge request gitlab-org/gitlab-ce!14868

package.json

@@ -66,7 +66,7 @@
     "vue-loader": "^11.3.4",
     "vue-resource": "^1.3.4",
     "vue-template-compiler": "^2.2.6",
-    "vuex": "^2.3.1",
+    "vuex": "^3.0.0",
     "webpack": "^3.5.5",
     "webpack-bundle-analyzer": "^2.8.2",
     "webpack-stats-plugin": "^0.1.5"

yarn.lock

@@ -6405,9 +6405,9 @@ vue@^2.2.6:
   version "2.2.6"
   resolved "https://registry.yarnpkg.com/vue/-/vue-2.2.6.tgz#451714b394dd6d4eae7b773c40c2034a59621aed"
 
-vuex@^2.3.1:
-  version "2.3.1"
-  resolved "https://registry.yarnpkg.com/vuex/-/vuex-2.3.1.tgz#cde8e997c1f9957719bc7dea154f9aa691d981a6"
+vuex@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/vuex/-/vuex-3.0.0.tgz#98b4b5c4954b1c1c1f5b29fa0476a23580315814"
 
 watchpack@^1.4.0:
   version "1.4.0"