build: remove commit hook for git-cz

"Prepare commit message" hook runs not only on commit, but also on a variety of other git tasks such
as rebase and merge, sometimes in an automated way from IDE (Jetbrains IDEs do that). git-cz utility
wasn't built with this in mind, and leads to bad developer experience. We can use already existing
`npm run commit` script for this. Also `"prepare"` npm hook runs when a package is packaged (`npm
pack`), and `husky` is intended to be run on install.

package.json

@@ -12,7 +12,7 @@
     "lint": "next lint",
     "format:check": "prettier --check --ignore-path .gitignore .",
     "format:fix": "prettier --write --ignore-path .gitignore .",
-    "prepare": "husky",
+    "postinstall": "husky",
     "commit": "git-cz"
   },
   "config": {