op-node: Fix maxDataSize calculation in ChannelOut.OutputFrame

Bedrock frames have a fixed overhead of 23 bytes.

Also removed the extra byte that was reserved for the version because
the calling sites of OutputFrame() already subtract this byte from their
maxSize arguments. This makes sense because the calling sites are
responsible for handling the correct overall tx data size.

op-node/rollup/derive/channel_out.go

@@ -133,9 +133,8 @@ func (co *ChannelOut) OutputFrame(w *bytes.Buffer, maxSize uint64) error {
 
 	// Copy data from the local buffer into the frame data buffer
 	// Don't go past the maxSize with the fixed frame overhead.
-	// Fixed overhead: 32 + 8 + 2 + 4 + 1  = 47 bytes.
-	// Add one extra byte for the version byte (for the entire L1 tx though)
-	maxDataSize := maxSize - 47 - 1
+	// Fixed overhead: 16 + 2 + 4 + 1 = 23 bytes.
+	maxDataSize := maxSize - 23
 	if maxDataSize > uint64(co.buf.Len()) {
 		maxDataSize = uint64(co.buf.Len())
 		// If we are closed & will not spill past the current frame