Build fails on Java 21 with Gradle 8.1

[sacoft]

System

• OS: Fedora 42
• Java: 21.0.8
• Gradle: 8.1
• Minecraft version: 1.19.4 (as set in gradle.properties)
• Project version: lumina-client-alpha-2.6.1

Steps Taken / Attempted Fixes

• Tried updating Gradle wrapper
• Checked and set JAVA_HOME
• Cleared Gradle cache

Issue

Building the project fails with the following error: It appears that the project is not fully compatible with Java 21 and Gradle 8.1. The issue occurs even after clearing Gradle caches and attempting to update the Gradle wrapper. This prevents the project from building from source.