Revert "migrate from yarn to npm"

This reverts commit 42c75194ed.

package.json

@@ -7,14 +7,14 @@
   "dependencies": {
     "@sanity/block-content-to-react": "^3.0.0",
     "country-flag-icons": "^1.5.13",
-    "gatsby": "^5.14.1",
+    "gatsby": "^5.14.0",
     "gatsby-plugin-image": "^3.14.0",
     "gatsby-plugin-manifest": "^5.14.0",
     "gatsby-plugin-react-helmet": "^6.14.0",
-    "gatsby-plugin-react-i18next": "^1.2.3",
+    "gatsby-plugin-react-i18next": "^3.0.1",
     "gatsby-plugin-sharp": "^5.14.0",
     "gatsby-source-filesystem": "^5.14.0",
-    "gatsby-source-sanity": "^7.0.7",
+    "gatsby-source-sanity": "^7.9.1",
     "gatsby-transformer-sharp": "^5.14.0",
     "i18next": "^23.16.4",
     "i18next-browser-languagedetector": "^8.0.0",