Update dependency com.android.tools:r8 to v8.11.18

Author: renovate[bot]

gradle/libs.versions.toml

@@ -1,5 +1,5 @@
 [libraries]
 junit = "junit:junit:4.13.2"
 assertk = "com.willowtreeapps.assertk:assertk:0.28.1"
-r8 = "com.android.tools:r8:8.7.18"
+r8 = "com.android.tools:r8:8.11.18"
 kotlin-gradle-plugin = "org.jetbrains.kotlin:kotlin-gradle-plugin:2.2.0"