pin psycopg2-binary on macOS/python 3.9

[ManuelHu]

There are no psycopg2-binary wheels for python 3.9 on the github macOS-latest (arm64) runner.

• Upstream states it would not possible any more to produce wheels for this combination.
• This would (probably) fix the macOS-latest CI jobs for all our packages dependant on pylegendmeta
• but this would (unfortunately) also limit actual users from building newer wheels from source on their machines...

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 71.95%. Comparing base (c97b445) to head (838ca85).
Report is 32 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #64   +/-   ##
=======================================
  Coverage   71.95%   71.95%           
=======================================
  Files           8        8           
  Lines         813      813           
=======================================
  Hits          585      585           
  Misses        228      228           

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