Update dependency io.github.goooler.shadow:shadow-gradle-plugin to v8.1.5

Author: renovate[bot]

gradle.properties

@@ -9,7 +9,7 @@ project_vcs=https://github.com/melix/jmh-gradle-plugin.git
 jacocoVersion      = 0.8.11
 jmhVersion         = 1.37
 shadowVersion      = 7.1.2
-shadowForkVersion  = 8.1.3
+shadowForkVersion  = 8.1.5
 spockVersion       = 2.3-groovy-3.0
 
 org.gradle.jvmargs=-Xmx4g -Dfile.encoding=UTF-8