Security Fix for CSRF Protection Middleware

Before this release, in versions 4.5.7 and below, the CSRF Protection Middleware did not treat requests including Content-Types with uppercase letters (e.g., Application/x-www-form-urlencoded) as potential attacks, allowing them to pass.

This could cause unexpected behavior, leading to a vulnerability. If you are using the CSRF Protection Middleware, please upgrade to version 4.5.8 or higher immediately.

For more details, see the report here: https://github.com/honojs/hono/security/advisories/GHSA-rpfr-3m35-5vx5