fix #1204: c2st with constant features; fix pyright.

[janfb]

Fixes #1204

[codecov]

Codecov Report

Attention: Patch coverage is 95.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 75.60%. Comparing base (ba19688) to head (983dfea).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1205      +/-   ##
==========================================
- Coverage   84.55%   75.60%   -8.95%     
==========================================
  Files          96       96              
  Lines        7603     7630      +27     
==========================================
- Hits         6429     5769     -660     
- Misses       1174     1861     +687     

Flag	Coverage Δ
unittests	75.60% <95.00%> (-8.95%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
sbi/diagnostics/lc2st.py	95.95% <100.00%> (-0.08%)	⬇️
sbi/diagnostics/tarp.py	54.94% <100.00%> (-23.08%)	⬇️
sbi/inference/snle/snle_base.py	93.87% <100.00%> (+0.06%)	⬆️
sbi/inference/snpe/snpe_base.py	91.01% <100.00%> (+0.05%)	⬆️
sbi/inference/snre/snre_base.py	94.49% <100.00%> (+0.05%)	⬆️
sbi/samplers/vi/vi_divergence_optimizers.py	80.26% <100.00%> (-6.61%)	⬇️
sbi/utils/metrics.py	39.30% <100.00%> (-54.62%)	⬇️
sbi/utils/restriction_estimator.py	78.08% <100.00%> (-7.52%)	⬇️
sbi/utils/sbiutils.py	78.43% <100.00%> (-8.13%)	⬇️
sbi/analysis/plot.py	66.15% <0.00%> (ø)
... and 1 more

... and 20 files with indirect coverage changes

[michaeldeistler]

Great, thanks a lot! Small comment below.