Draft release notes for v4.1.1

[ctb]

git log --oneline v4.1.0..latest:

4.1.1 release notes

This release fixes a minor bug, provides some refactorings, and dramatically decreases memory consumption for sourmash gather --linear (which is, admittedly, a niche use case :).

No major new features.

Bug fixes and performance improvements:

• Unload data with sourmash gather --linear on SBTs ([MRG] unload data on iteration over SBT leaves #1534)
• Fix sourmash gather --no-prefetch when used w/abund signatures ( [MRG] fix gather against signatures with abundances, in a new place. #1528)
• Fix sourmash index to not create directory for .sbt.zip output ([MRG] fix SBT FSStorage to not create directory for .sbt.zip output #1539)

Major refactoring and new internal functionality:

• Add FrozenMinHash to better support separation of frozen and mutable data actions ([MRG] Add FrozenMinHash #1508)

Refactoring and cleanup:

• Improved error handling and testing for pathlist loading ([MRG] Added tests for the function load_pathlist_from_file #1469)
• Updated some tests to use sourmash sketch instead of sourmash compute ([MRG] Changing sourmash compute to sourmash sketch in tests/test_sourmash.py #1536)
• Refactor sourmash lca summarize to remove unnecessary if statements, improve tests ([MRG] refactor lca_summarize to remove unnecessary if statements #1540)

[ctb]

released!