Configure Gradle parallelism and Kotlin compiler in `sdk-sync` (#1448)

    #[instrument(skip(self))]

    fn aws_sdk_assemble(&self) -> Result<()> {

        info!("Generating the SDK...");

        let mut command = Command::new("./gradlew");

        command.arg("--no-daemon"); // Don't let Gradle continue running after the build

        command.arg("--no-parallel"); // Disable Gradle parallelism

        command.arg("--max-workers=1"); // Cap the Gradle workers at 1

        command.arg("--info"); // Increase logging verbosity for failure debugging

        // Customize the Gradle daemon JVM args (these are required even with `--no-daemon`

        // since Gradle still forks out a daemon process that gets terminated at the end)

        command.arg(format!(

            "-Dorg.gradle.jvmargs={}",

            [

                // Retain default Gradle JVM args

                "-Xmx512m",

                "-XX:MaxMetaspaceSize=256m",

                // Disable incremental compilation and caching since we're compiling exactly once per commit

                "-Dkotlin.incremental=false",

                "-Dkotlin.caching.enabled=false",

                // Run the compiler in the gradle daemon process to avoid more forking thrash

                "-Dkotlin.compiler.execution.strategy=in-process"

            ]

            .join(" ")

        ));

        // Disable Smithy's codegen parallelism in favor of sdk-sync parallelism

        command.arg(format!(

            "-Djava.util.concurrent.ForkJoinPool.common.parallelism={}",

            self.smithy_parallelism

        ));

        command.arg("-Paws.fullsdk=true");

        command.arg(format!(

            "-Paws.sdk.previous.release.versions.manifest={}",