Remove kamon tracing

[t-bast]

It's costly, we're not using it, and it's too invasive.
There's no reason to keep it at the moment.

[codecov-io]

Codecov Report

Merging #1662 (100a808) into master (dd8975a) will decrease coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1662      +/-   ##
==========================================
- Coverage   85.92%   85.88%   -0.04%     
==========================================
  Files         151      151              
  Lines       11471    11418      -53     
  Branches      505      506       +1     
==========================================
- Hits         9856     9806      -50     
+ Misses       1615     1612       -3     

Impacted Files	Coverage Δ
...ore/src/main/scala/fr/acinq/eclair/PimpKamon.scala	100.00% <ø> (ø)
...lockchain/bitcoind/rpc/ExtendedBitcoinClient.scala	92.85% <ø> (ø)
...clair/payment/send/MultiPartPaymentLifecycle.scala	95.03% <100.00%> (-0.21%)	⬇️
...r/acinq/eclair/payment/send/PaymentLifecycle.scala	92.80% <100.00%> (-0.53%)	⬇️
...e/src/main/scala/fr/acinq/eclair/router/Sync.scala	98.30% <100.00%> (-0.09%)	⬇️
...main/scala/fr/acinq/eclair/router/Validation.scala	91.11% <100.00%> (-0.30%)	⬇️
...cinq/eclair/blockchain/bitcoind/zmq/ZMQActor.scala	90.00% <0.00%> (-5.00%)	⬇️
...nq/eclair/blockchain/electrum/ElectrumWallet.scala	80.51% <0.00%> (+0.25%)	⬆️
...nq/eclair/blockchain/electrum/ElectrumClient.scala	73.89% <0.00%> (+0.36%)	⬆️
...q/eclair/blockchain/electrum/ElectrumWatcher.scala	76.98% <0.00%> (+1.58%)	⬆️

[pm47]

Is the issue more the cost, or the invasiveness? If it's the former, then why not simply disable it?

[t-bast]

It's mostly the invasiveness (the cost is an added benefit, but it's quite negligible).