Bump Kotlin version for Compose Gradle plugin tests to 2.2.20 (#5459)

## Testing
Running the existing tests

## Release Notes
N/A

gradle-plugins/compose/src/test/test-projects/application/proguard/main-methods.expected.txt

@@ -1,5 +1,5 @@
 keptByKeepRule
-keptByKeepRule$lambda$5
+keptByKeepRule$lambda$0
 main
 mainShape
-mainShape$lambda$2
+mainShape$lambda$0

gradle-plugins/gradle.properties

@@ -11,7 +11,7 @@ dev.junit.parallel=false
 compose.version=1.9.0
 compose.material3.version=1.9.0-beta03
 # The latest version of Kotlin compatible with compose.tests.compiler.version. Used only in tests/CI.
-compose.tests.kotlin.version=2.2.0
+compose.tests.kotlin.version=2.2.20
 # __SUPPORTED_GRADLE_VERSIONS__
 # Don't forget to edit versions in .github/workflows/gradle-plugin.yml as well
 # and Publish.Subtasks.buildTypes.gradle.GradlePluginTestKt#gradleVersions in the TC config