Update okio to v3.15.0

Author: renovate[bot]

gradle/libs.versions.toml

@@ -18,7 +18,7 @@ kotlinpoet = "2.0.0"
 ktlint = "0.48.2"
 moshi = "1.15.2"
 okhttp = "5.0.0-alpha.14"
-okio = "3.9.1"
+okio = "3.15.0"
 protobuf = "4.31.1"
 protobufGradlePlugin = "0.9.5"