Fix dynamic agent loading warning in Gradle

In newer versions java, dynamically loaded agents will be disallowed. Warnings like the following would be logged by your test runner.

WARNING: A Java agent has been loaded dynamically (/Users/cwalker/.gradle/caches/modules-2/files-2.1/net.bytebuddy/byte-buddy-agent/1.14.6/46e2545d7a97b6ccb195621650c5957279eb4812/byte-buddy-agent-1.14.6.jar)
WARNING: If a serviceability tool is in use, please run with -XX:+EnableDynamicAgentLoading to hide this warning
WARNING: If a serviceability tool is not in use, please run with -Djdk.instrument.traceUsage for more information
WARNING: Dynamic loading of agents will be disallowed by default in a future release

To fix this, we can get add a new agent configuration and map dependencies from that configuration to the -javaagent flag.

Using the new test-suites plugin, that would look like the following.

val testAgent by configurations.creating

dependencies {
    testAgent("net.bytebuddy:byte-buddy-agent:1.14.6")
}

testing {
    suites {
        val test by getting(JvmTestSuite::class) {
            useJUnitJupiter("5.10.1")
            dependencies {
                implementation("org.jetbrains.kotlin:kotlin-reflect:1.9.22")
                implementation("io.mockk:mockk:1.13.9")
            }
            targets.configureEach {
                testTask.configure {
                    jvmArgs(testAgent.files.map { "-javaagent:${it.absolutePath}" })
                }
            }
        }
    }
}

Follow the upstream issue for updates.