scripted-diff: Use std::span over Span

-BEGIN VERIFY SCRIPT-

 ren() { sed -i "s!\<$1\>!$2!g" $( git grep -l "$1" -- "./src" ":(exclude)src/span.h" ":(exclude)src/leveldb/db/log_test.cc" ) ; }

 ren Span            std::span
 ren AsBytes         std::as_bytes
 ren AsWritableBytes std::as_writable_bytes

 sed -i 's!SpanPopBack(Span!SpanPopBack(std::span!g' ./src/span.h

-END VERIFY SCRIPT-

src/net_processing.cpp

@@ -2282,7 +2282,7 @@ void PeerManagerImpl::ProcessGetBlockData(CNode& pfrom, Peer& peer, const CInv&
             pfrom.fDisconnect = true;
             return;
         }
-        MakeAndPushMessage(pfrom, NetMsgType::BLOCK, Span{block_data});
+        MakeAndPushMessage(pfrom, NetMsgType::BLOCK, std::span{block_data});
         // Don't set pblock as we've sent the block
     } else {
         // Send block from disk