I finally resolved the issue!
It turns out I had multiple PhpStorm versions installed.
Initially, I deleted the plugins folder for PhpStorm 2024.3, but the CodeGeeX plugin was still present in the plugins folder for PhpStorm 2024.2. It seems PhpStorm was still accessing the plugin from that older version!
The error was completely resolved once I removed the plugin from the 2024.2 folder.