[PR #9174/98b363e4 backport][3.11] Add a cache to must_be_empty_body

[patchback]

This is a backport of PR #9174 as merged into master (98b363e).

What do these changes do?

Nearly all the calls are going to be the same so we can cache the logic

I couldn't figure out how to avoid this call in most cases like #9172 so a cache made more sense.

Are there changes in behavior for the user?

no

Is it a substantial burden for the maintainers to support this?

no

related issue #2779

before

after

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Please upload report for BASE (3.11@45dd34c). Learn more about missing BASE report.
Report is 1 commits behind head on 3.11.

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             3.11    #9191   +/-   ##
=======================================
  Coverage        ?   97.78%           
=======================================
  Files           ?      108           
  Lines           ?    34647           
  Branches        ?     4125           
=======================================
  Hits            ?    33880           
  Misses          ?      573           
  Partials        ?      194           

Flag	Coverage Δ
CI-GHA	97.68% <100.00%> (?)
OS-Linux	97.36% <100.00%> (?)
OS-Windows	94.94% <100.00%> (?)
OS-macOS	97.06% <100.00%> (?)
Py-3.10.11	97.14% <100.00%> (?)
Py-3.10.14	96.89% <100.00%> (?)
Py-3.10.15	97.00% <100.00%> (?)
Py-3.11.10	96.80% <100.00%> (?)
Py-3.11.9	97.23% <100.00%> (?)
Py-3.12.5	97.08% <100.00%> (?)
Py-3.12.6	97.14% <100.00%> (?)
Py-3.9.13	97.04% <100.00%> (?)
Py-3.9.19	96.91% <100.00%> (?)
Py-3.9.20	96.80% <100.00%> (?)
Py-pypy7.3.16	96.58% <100.00%> (?)
VM-macos	97.06% <100.00%> (?)
VM-ubuntu	97.36% <100.00%> (?)
VM-windows	94.94% <100.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

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