Apply suggestion from @Copilot

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: Goooler

src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/internal/RelocatorRemapper.kt

@@ -27,7 +27,14 @@ internal class RelocatorRemapper(
 
   override fun map(internalName: String): String = mapName(internalName)
 
-  fun mapPath(path: String): String = map(path.substring(0, path.indexOf('.')))
+  fun mapPath(path: String): String {
+    val dotIndex = path.indexOf('.')
+    return if (dotIndex == -1) {
+      path // Return the original path if no period is found
+    } else {
+      map(path.substring(0, dotIndex))
+    }
+  }
 
   private fun mapName(name: String, mapLiterals: Boolean = false): String {
     var newName = name