duplication of 'large number' in warning

[turnmanh]

What does this implement/fix? Explain your changes

The warning on the number of chains for batched sampling for a MCMC Posterior hat larger number twice in the string.

Also, despite reducing the number of chains, reducing the batch size might be a suitable solution as well.

Does this close any currently open issues?

No.

Any relevant code examples, logs, error output, etc?

No.

Any other comments?

No.

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.48%. Comparing base (18f92b1) to head (9d7f5b3).
Report is 3 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #1391       +/-   ##
===========================================
- Coverage   89.31%   78.48%   -10.84%     
===========================================
  Files         119      119               
  Lines        8779     8779               
===========================================
- Hits         7841     6890      -951     
- Misses        938     1889      +951     

Flag	Coverage Δ
unittests	78.48% <ø> (-10.84%)	⬇️

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

Files with missing lines	Coverage Δ
sbi/inference/posteriors/mcmc_posterior.py	86.14% <ø> (-0.75%)	⬇️

... and 32 files with indirect coverage changes

[janfb]

Thanks for fixing this @turnmanh !

Tests and type checks are currently failing due to a change / bug in a recent pymc release, see #1390

Let's wait til that one is merged.