build(deps): bump net.dv8tion:JDA from 5.0.0-beta.13 to 5.0.0-beta.15

Bumps [net.dv8tion:JDA](https://github.com/discord-jda/JDA) from 5.0.0-beta.13 to 5.0.0-beta.15.
- [Release notes](https://github.com/discord-jda/JDA/releases)
- [Commits](discord-jda/JDA@v5.0.0-beta.13...v5.0.0-beta.15)

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

Signed-off-by: dependabot[bot] <[email protected]>

app/build.gradle

@@ -40,7 +40,7 @@ dependencies {
  implementation "com.deepl.api:deepl-java:1.3.0"
  implementation 'com.vdurmont:emoji-java:5.1.1'
  implementation 'it.sauronsoftware.cron4j:cron4j:2.2.5'
- implementation "net.dv8tion:JDA:5.0.0-beta.13"
+ implementation "net.dv8tion:JDA:5.0.0-beta.15"
  implementation 'org.apache.commons:commons-lang3:3.13.0'
  implementation 'org.ocpsoft.prettytime:prettytime:5.0.7.Final'
 }