DM-53233: Add resource cleanup interface to Butler

[dhirving]

Add a close() method and a context manager implementation to Butler, to prevent resource leaks. This allows users to ensure that database connections are closed promptly.

Checklist

• ran Jenkins
• added a release note for user-visible changes to doc/changes
• (if changing dimensions.yaml) make a copy of dimensions.yaml in configs/old_dimensions

[codecov]

Codecov Report

❌ Patch coverage is 78.93891% with 131 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.45%. Comparing base (f17f41f) to head (b9ecf4b).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
python/lsst/daf/butler/script/exportCalibs.py	0.00%	31 Missing ⚠️
python/lsst/daf/butler/script/queryCollections.py	76.40%	18 Missing and 3 partials ⚠️
...thon/lsst/daf/butler/script/certifyCalibrations.py	0.00%	14 Missing ⚠️
...on/lsst/daf/butler/script/queryDimensionRecords.py	69.04%	5 Missing and 8 partials ⚠️
python/lsst/daf/butler/script/queryDataIds.py	80.00%	7 Missing and 3 partials ⚠️
python/lsst/daf/butler/script/collectionChain.py	58.82%	3 Missing and 4 partials ⚠️
python/lsst/daf/butler/script/transferDatasets.py	0.00%	7 Missing ⚠️
python/lsst/daf/butler/script/_associate.py	0.00%	4 Missing ⚠️
python/lsst/daf/butler/script/queryDatasetTypes.py	69.23%	3 Missing and 1 partial ⚠️
python/lsst/daf/butler/_labeled_butler_factory.py	91.17%	1 Missing and 2 partials ⚠️
... and 9 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1288      +/-   ##
==========================================
+ Coverage   89.42%   89.45%   +0.03%     
==========================================
  Files         367      367              
  Lines       49540    49739     +199     
  Branches     5837     5850      +13     
==========================================
+ Hits        44299    44496     +197     
  Misses       3856     3856              
- Partials     1385     1387       +2     

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