Regression in sr speed in nk v3.0b3

Created by: PhilipVinc

as opposed to v3.0b2. Both end up using qgtonthefly

cc @inailuig

netket on  tags/v3.0b2 [$] via netket_env via 🐍 system 
➜ python -i Examples/Ising1d/ising1d_sr.py 
/home/filippovicentini/Dropbox/Ricerca/Codes/Python/netket/netket/variational.py:29: FutureWarning: The `netket.variational` module is deprecated. Use `netket.vqs` instead.
To fix this warning, change `netket.variational.MCState to `netket.vqs.MCState`.
  _warn_deprecation(
WARNING:absl:No GPU/TPU found, falling back to CPU. (Set TF_CPP_MIN_LOG_LEVEL=0 and rerun for more info.)
No output specified (out=[apath|nk.logging.JsonLogger(...)]).Running the optimization but not saving the output.
100%|███████████████████████████████████████████████████████████████| 300/300 [00:11<00:00, 25.91it/s, Energy=-25.5005 ± 0.0045 [σ²=0.0208, R̂=0.9969]]]
>>> 

netket on  tags/v3.0b2 [$✘?] via netket_env via 🐍 system took 19s 
➜ git checkout v3.0b3                      
Previous HEAD position was cd6eb5a3 Fix publish-to-pypi (#733)
HEAD is now at a2e0949a Update CHANGELOG.md for new release (#807)

netket on  tags/v3.0b3 [$?] via netket_env via 🐍 system 
➜ python -i Examples/Ising1d/ising1d_sr.py 
/home/filippovicentini/Dropbox/Ricerca/Codes/Python/netket/netket/variational.py:29: FutureWarning: The `netket.variational` module is deprecated. Use `netket.vqs` instead.
To fix this warning, change `netket.variational.MCState to `netket.vqs.MCState`.
  _warn_deprecation(
WARNING:absl:No GPU/TPU found, falling back to CPU. (Set TF_CPP_MIN_LOG_LEVEL=0 and rerun for more info.)
No output specified (out=[apath|nk.logging.JsonLogger(...)]).Running the optimization but not saving the output.
100%|███████████████████████████████████████████████████████████████| 300/300 [00:15<00:00, 19.22it/s, Energy=-25.4865 ± 0.0045 [σ²=0.0204, R̂=0.9989]]]