Update dependency io.github.java-diff-utils:java-diff-utils to v4.15 (#63)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

gradle/libs.versions.toml

@@ -2,7 +2,7 @@
 
 kotlinGradle = "1.9.25"
 
-javaDiffUtils = "4.12"
+javaDiffUtils = "4.15"
 junit = "5.11.3"
 kotest = "5.9.1"
 kotlinx-bcv = "0.13.2"