Merge bitcoin/bitcoin#31996: doc: link to benchcoin over bitcoinperf

611999e doc: link to benchcoin over bitcoinperf (fanquake)

Pull request description:

  Seems like linking to https://github.com/bitcoin-dev-tools/benchcoin is now the best thing to do here. If not, we can just drop the other links.

ACKs for top commit:
  l0rinc:
    ACK 611999e
  laanwj:
    ACK 611999e
  hebasto:
    ACK 611999e. I agree. I've had a great experience using it.

Tree-SHA512: 558060bec92099befaa047e9192e5172e6a0cdfc5530d1f8b4d64ac717ce999a993d39c5d108fa9df3e30b2fc089e31d720f344153381e7c53f0ed40938ae1e0

Author: hebasto

doc/benchmarking.md

@@ -74,6 +74,4 @@ specifically aimed at exploring the possible input space.
 Going Further
 --------------------
 
-To monitor Bitcoin Core performance more in depth (like reindex or IBD): https://github.com/chaincodelabs/bitcoinperf
-
-To generate Flame Graphs for Bitcoin Core: https://github.com/eklitzke/bitcoin/blob/flamegraphs/doc/flamegraphs.md
+To monitor Bitcoin Core performance more in depth (like reindex or IBD): https://github.com/bitcoin-dev-tools/benchcoin