Test larger batches with more efficient queries for datastore export

[dhirving]

This reduces export time for butler_transform by about 30-40%, but only when using psycopg3. We're still on psycopg2, though psycopg3 will become the default in the next version of sqlalchemy.

psycopg2 never uses bind parameters, so it still generates a large new query for each execution. With psycopg3 it uses a single bind parameter for the list of dataset IDs, and it is able to cache and re-use the query, and use a more efficient binary encoding for sending the UUIDs.

Checklist

• ran Jenkins
• added a release note for user-visible changes to doc/changes
• (if changing dimensions.yaml) make a copy of the updated dimensions.yaml in configs/old_dimensions and update the list in doc/lsst.daf.butler/dimensions.rst

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.62%. Comparing base (4a958a8) to head (a4df221).
⚠️ Report is 3 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1377   +/-   ##
=======================================
  Coverage   89.62%   89.62%           
=======================================
  Files         373      373           
  Lines       50772    50792   +20     
  Branches     5913     5914    +1     
=======================================
+ Hits        45502    45521   +19     
  Misses       3880     3880           
- Partials     1390     1391    +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.