⬆️ Update Gradle to 9.8.1 and fix Java 25 builds

[NoltoxGit]

Summary

Update the build tooling to support running Gradle with Java 25.

• Upgrade Gradle from 9.0 to 9.8.1.
• Regenerate the wrapper JAR and both launcher scripts.
• Upgrade the Foojay resolver from 0.9.0 to 1.0.0 to fix its reference to the removed JvmVendorSpec.IBM_SEMERU constant.

Changes are limited to build tooling. The main module retains Java 21 bytecode.

Validation

• Full multi-module gradlew.bat clean build --console=plain completed successfully with Java 25.
• Verified that both Windows and Unix wrapper scripts launch Gradle 9.8.1.
• The personal integration branch also builds successfully.
• Existing Gradle test tasks report NO-SOURCE.