Bump nuxt from 2.15.4 to 2.15.6

Bumps [nuxt](https://github.com/nuxt/nuxt.js) from 2.15.4 to 2.15.6.
- [Release notes](https://github.com/nuxt/nuxt.js/releases)
- [Changelog](https://github.com/nuxt/nuxt.js/blob/dev/RELEASE_PLAN.md)
- [Commits](https://github.com/nuxt/nuxt.js/compare/v2.15.4...v2.15.6)

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

package.json

@@ -13,14 +13,14 @@
   },
   "dependencies": {
     "@nuxtjs/axios": "^5.13.6",
-    "dotenv": "^10.0.0",
+    "dotenv": "^8.2.0",
     "moment": "^2.29.1",
     "node-sass": "^5.0.0",
-    "nuxt": "^2.15.7",
+    "nuxt": "^2.15.6",
     "nuxt-buefy": "^0.3.31",
-    "nuxt-shopify": "^1.10.11",
+    "nuxt-shopify": "^1.10.7",
     "sass-loader": "^10.1.1",
-    "vuex-persistedstate": "^4.0.0"
+    "vuex-persistedstate": "^3.2.0"
   },
   "devDependencies": {
     "@nuxtjs/eslint-config": "^2.0.2",