Kotlin stdlib should not be a pom dep

[bbakerman]

See #227

Local maven publish says

<dependencies>
    <dependency>
      <groupId>org.reactivestreams</groupId>
      <artifactId>reactive-streams</artifactId>
      <version>1.0.3</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>org.jspecify</groupId>
      <artifactId>jspecify</artifactId>
      <version>1.0.0</version>
      <scope>compile</scope>
    </dependency>
  </dependencies>
  <name>java-dataloader</name>
  <description>A pure Java 11 port of Facebook Dataloader</description>
  <url>https://github.com/graphql-java/java-dataloader</url>
  <inceptionYear>2017</inceptionYear>