A bit more consistent SignalGroup iter

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 100.00%. Comparing base (f4ac7c3) to head (f8e9906).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #289 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 22 22 Lines 1930 1933 +3 ========================================= + Hits 1930 1933 +3 ```

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[codspeed-hq[bot]]

CodSpeed Performance Report

Merging #289 will improve performances by 13.72%

_{Comparing getzze:correct-group-iter (f8e9906) with main (f4ac7c3)}

Summary

⚡ 1 improvements ✅ 65 untouched benchmarks

Benchmarks breakdown

	Benchmark	main	getzze:correct-group-iter	Change
⚡	test_emit_time[lambda-2]	127.9 µs	112.5 µs	+13.72%

[tlambert03]

looks good to me! thanks @getzze.
side question: I notice you mark most of your PRs as draft, and don't seem to mark them as ready for review. Should I assume that they're ready to go if all tests are passing and you haven't touched it for a few days?

[getzze]

I'm not 100% when to use draft or not, but this PR is not a draft indeed :)