Bump net.dv8tion:JDA from 5.6.1 to 6.0.0-preview

Bumps [net.dv8tion:JDA](https://github.com/discord-jda/JDA) from 5.6.1 to 6.0.0-preview.
- [Release notes](https://github.com/discord-jda/JDA/releases)
- [Commits](https://github.com/discord-jda/JDA/commits)

---
updated-dependencies:
- dependency-name: net.dv8tion:JDA
  dependency-version: 6.0.0-preview
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

build.gradle.kts

@@ -30,7 +30,7 @@ val mariaDBVersion = "3.5.4"
 
 val kotlinxSerializationVersion = "1.9.0"
 val kamlVersion = "0.83.0"
-val jdaVersion = "5.6.1"
+val jdaVersion = "6.0.0-preview"
 val jdaKtxVersion = "0.12.0"
 val secretLabKotlinVersion = "0.4.3"
 val logbackVersion = "1.5.18"