op-batcher: Check whether the throttling interval can be removed

[sebastianst]

We should check whether the throttling interval ticker in the throttling loop actually makes sense, since the threshold loop is already triggered by the l2BlockAdded signal.

If not, we should remove it and then disable throttling by one (or both) of the throttling parameters being 0.

I'm wondering now, what's actually the purpose of enabling throttling on this ticker? The only event that can increase pending bytes is adding a block to the queue, which is already covered by the l2BlockAdded event channel. I'll get this PR in regardless, as it doesn't hurt, but we should investigate whether we can simplify by removing it. We should then probably revert back to disabling this feature if one of the thresholds is set to 0.

Originally posted by @sebastianst in #12735 (comment)