Update plugin com.gradleup.shadow to v8.3.9

Author: renovate[bot]

settings.gradle.kts

@@ -23,7 +23,7 @@ dependencyResolutionManagement {
 
     versionCatalogs {
         create("libs") {
-            version("shadow", "8.3.8")
+            version("shadow", "8.3.9")
             version("bom", "1.4.2")
 
             library("mycelium.bom", "net.onelitefeather", "mycelium-bom").versionRef("bom")