chore: drop disabled husky pre-push hook and dependency

The .husky/_pre-push script was renamed from pre-push, which
disables it under husky v9. With no remaining active hooks, husky
is dead weight, so remove the dependency and prepare script too.

package.json

@@ -12,7 +12,6 @@
     "lint:fix": "oxlint --fix",
     "fmt": "oxfmt",
     "fmt:check": "oxfmt --check",
-    "prepare": "husky",
     "theme:light": "esno _scripts/change-theme-light.ts",
     "theme:dark": "esno _scripts/change-theme-dark.ts"
   },
@@ -84,7 +83,6 @@
     "eslint-plugin-simple-import-sort": "^12.1.1",
     "eslint-plugin-unused-imports": "^4.4.1",
     "esno": "^4.8.0",
-    "husky": "^9.1.7",
     "oxfmt": "^0.42.0",
     "oxlint": "^1.57.0",
     "prettier": "^3.8.1",