gh-134584: Revert partially #135860

[Fidget-Spinner]

This fixes a refleak.

• Issue: Eliminate redundant refcounting in the JIT #134584

[Zheaoli]

Should I change #136070 to avoid the refleak?

[vstinner]

LGTM: I confirm that this change fix the refleak. I didn't review the change itself, it just looks good to me :-)

$ ./python -m test test.test_multiprocessing_fork.test_threads -R 3:3 
(...)
Result: SUCCESS

[Fidget-Spinner]

Should I change #136070 to avoid the refleak?

The PR can't be fixed/ the code generator won't allow the change until #142604 is merged.