fix: package.json & yarn.lock to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-BRACES-6838727
- https://snyk.io/vuln/SNYK-JS-MICROMATCH-6838728

package.json

@@ -29,11 +29,11 @@
     "formik": "^2.2.6",
     "framer-motion": "^3.2.1",
     "gatsby-plugin-google-analytics": "^2.9.0",
-    "jest": "^26.6.3",
+    "jest": "^27.0.0",
     "js-cookie": "^2.2.1",
     "lodash": "^4.17.20",
     "mongoose": "^5.11.12",
-    "next": "^10.0.5",
+    "next": "^12.0.8",
     "next-connect": "^0.9.1",
     "next-cookies": "^2.0.3",
     "polished": "^4.0.5",
@@ -58,7 +58,7 @@
     "styled-components": "^5.2.1",
     "styled-system": "^5.1.5",
     "swr": "^0.4.0",
-    "ts-jest": "^26.4.4",
+    "ts-jest": "^27.0.0",
     "typescript": "^4.1.3",
     "typography": "^0.16.19",
     "typography-plugin-code": "^0.16.19",