Fix package.json engines and required Node version (#950)

Including "pnpm" in the engines field of your package.json for a library
is generally not recommended, even if you use it for building the
library. The engines field is typically used to specify runtime
environments (such as Node.js versions) that are required to run the
library, not the tools used to build or develop it. Most developers
expect the engines field to list only the runtime requirements, not
development tools like package managers.

package.json

@@ -38,8 +38,7 @@
   "main": "dist/client-side-validations.js",
   "module": "dist/client-side-validations.esm.js",
   "engines": {
-    "node": ">= 18.0",
-    "pnpm": "^9.12.1"
+    "node": ">= 18.12"
   },
   "packageManager": "pnpm@^9.12.1",
   "browserslist": [