Merge bitcoin/bitcoin#23881: doc: Remove TODO from block fuzz test

fa5d0b6ecd doc: Remove TODO from block fuzz test (MarcoFalke)

Pull request description:

  I don't see a reason to fix the TODO, as all call sites assume at least one tx in `vtx`. So remove it.

ACKs for top commit:
  fanquake:
    ACK fa5d0b6ecd

Tree-SHA512: 8fe03a5bdebf4d6dad00f410a1dc6449c485a4d61afb79ebcaa221489cde2a465fea981742fde130238ebed6d2f1f032aa4976726ee07b23fe7fb745b2728d46

src/test/fuzz/block.cpp

@@ -58,8 +58,6 @@ FUZZ_TARGET_INIT(block, initialize_block)
     (void)block.ToString();
     (void)BlockMerkleRoot(block);
     if (!block.vtx.empty()) {
-        // TODO: Avoid array index out of bounds error in BlockWitnessMerkleRoot
-        //       when block.vtx.empty().
         (void)BlockWitnessMerkleRoot(block);
     }
     (void)GetBlockWeight(block);