WorkerThread#blockOn implementation note is incorrect

[armanbilge]

blockOn may be invoked by directly using the WSTP as an ExecutionContext with scala.concurrent.blocking, no IO involved. So that's not sufficient justification for not using try/catch. Not sure if we can rejustify it, or just have to add it in.

cats-effect/core/jvm/src/main/scala/cats/effect/unsafe/WorkerThread.scala

Lines 923 to 933 in 9218648

	/**
	* A mechanism for executing support code before executing a blocking action.
	*
	* @note
	* There is no reason to enclose any code in a `try/catch` block because the only way this
	* code path can be exercised is through `IO.delay`, which already handles exceptions.
	*/
	override def blockOn[T](thunk: => T)(implicit permission: CanAwait): T = {
	prepareForBlocking()
	thunk
	}

[djspiewak]

So I think the conclusion of the note is correct even though the reasoning isn't. You can't get into blockOn without being already on the thread pool, which means we're going to be wrapped in a top level try/catch.