Update gatsby monorepo

Author: renovate[bot]

package.json

@@ -16,13 +16,13 @@
   },
   "dependencies": {
     "@lekoarts/gatsby-theme-minimal-blog": "2.4.0",
-    "gatsby": "2.20.36",
+    "gatsby": "5.12.10",
     "gatsby-plugin-ackee-tracker": "2.2.0",
-    "gatsby-plugin-manifest": "2.4.13",
+    "gatsby-plugin-manifest": "5.12.3",
     "gatsby-plugin-matomo": "0.8.3",
     "gatsby-plugin-netlify": "2.1.3",
-    "gatsby-plugin-offline": "3.2.13",
-    "gatsby-plugin-sitemap": "2.4.6",
+    "gatsby-plugin-offline": "6.12.3",
+    "gatsby-plugin-sitemap": "6.12.3",
     "react": "16.13.1",
     "react-dom": "16.13.1"
   },