DM-32499: deprecate butler prune-collections

[n8pease]

Checklist

• ran Jenkins
• added a release note for user-visible changes to doc/changes

[codecov]

Codecov Report

Merging #634 (7e22de7) into main (8be9c34) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main     #634   +/-   ##
=======================================
  Coverage   84.12%   84.12%           
=======================================
  Files         237      237           
  Lines       30183    30185    +2     
  Branches     5018     5018           
=======================================
+ Hits        25392    25394    +2     
  Misses       3646     3646           
  Partials     1145     1145           

Impacted Files	Coverage Δ
python/lsst/daf/butler/cli/cmd/commands.py	90.30% <100.00%> (+0.06%)	⬆️

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