Multiple line stat collectors aren't supported

If you try to add multiple LinesOfCodeStatCollectors, only the first one appears to have any effect. In this example, I only see Kotlin files. If I remove the kotlin one, I will see only java files. It seems like despite the unique string keys, duplicate types are still being filtered out.

 addStatCollector(
    com.squareup.invert.collectors.linesofcode.LinesOfCodeStatCollector(
      name = "Kotlin",
      fileExtensions = listOf("kt", "kts"),
    )
  )
 addStatCollector(
    com.squareup.invert.collectors.linesofcode.LinesOfCodeStatCollector(
      name = "Java",
      fileExtensions = listOf("java"),
    )
  )

Start by tracing addStatCollector and how LinesOfCodeStatCollector instances are registered or filtered, using the Kotlin and Java example in the issue. Confirm that distinct collector names do not prevent duplicate types from being removed; done means both Kotlin and Java files appear when both collectors are added.