DM-36174: Require Python 3.10.

[TallJimbo]

daf_butler will soon require 3.10, even if code directly in ctrl_mpexec does not yet.

Checklist

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

[codecov]

Codecov Report

Base: 83.35% // Head: 83.36% // Increases project coverage by +0.00% 🎉

Coverage data is based on head (e5e3b11) compared to base (5106228).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #203   +/-   ##
=======================================
  Coverage   83.35%   83.36%           
=======================================
  Files          48       48           
  Lines        3846     3848    +2     
  Branches      690      690           
=======================================
+ Hits         3206     3208    +2     
  Misses        470      470           
  Partials      170      170           

Impacted Files	Coverage Δ
python/lsst/ctrl/mpexec/mpGraphExecutor.py	86.55% <100.00%> (+0.08%)	⬆️
python/lsst/ctrl/mpexec/singleQuantumExecutor.py	74.91% <100.00%> (ø)

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