Update task engine to increment run_count when entering RUNNING state

[desertaxle]

Walks back some changes in #15424 to update run_count when a task run enters RUNNING instead of when the user code is run.

Checklist

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[cicdw]

Jw: would it be simpler to have an if new_state.is_running() then increment run count statement in set_state or will that have edge cases?

[desertaxle]

Yup, that does appear to work. Updated in 3fb2d68

[codspeed-hq]

CodSpeed Performance Report

Merging #15436 will not alter performance

_{Comparing fix-15424 (3fb2d68) with main (e248442)}

Summary

✅ 3 untouched benchmarks