bump com.google.testing.compile:compile-testing from 0.19 to 0.21.0 (via #1083)

Author: dependabot[bot]

build.gradle.kts

@@ -151,7 +151,7 @@ configure(libs) {
             dependency("com.github.spotbugs:spotbugs:4.8.3")
             dependency("com.github.tomakehurst:wiremock:3.0.1")
             dependency("com.google.inject:guice:7.0.0")
-            dependency("com.google.testing.compile:compile-testing:0.19")
+            dependency("com.google.testing.compile:compile-testing:0.21.0")
             dependency("com.puppycrawl.tools:checkstyle:10.17.0")
             dependency("com.squareup.retrofit2:retrofit:2.11.0")
             dependency("commons-io:commons-io:2.16.1")