Bump Gradle Wrapper from 8.12.1 to 8.13. (#175)

Release notes of Gradle 8.13 can be found here:
https://docs.gradle.org/8.13/release-notes.html

Signed-off-by: iokibot <31736373+iokibot@users.noreply.github.com>

Author: iokibot

gradle/wrapper/gradle-wrapper.jar

@@ -1,7 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionSha256Sum=8d97a97984f6cbd2b85fe4c60a743440a347544bf18818048e611f5288d46c94
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.12.1-bin.zip
+distributionSha256Sum=20f1b1176237254a6fc204d8434196fa11a4cfb387567519c61556e8710aed78
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.13-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME