- determine-jobs: trigger on changes to requirements_test.txt too; that
file is hashed into the venv cache key and installed during
restore-python, so a change there can alter the import environment.
- ci.yml: merge the --check and --har steps so we only run
importtime-waterfall once per job (was measuring twice: ~7-8s of
wasted CI time per run). Uses the new script/check_import_time.py
--check --har <path> combination; the HAR reflects the same
measurement that produced the pass/fail decision.
- script/check_import_time.py: refactor the CLI so --har is a standalone
option rather than a mutually-exclusive mode. --check and --update
each accept an optional --har PATH that writes the HAR from the same
subprocess invocation. Plain --har is still supported for local use.
- tests: add tests/script/test_check_import_time.py covering HAR parsing,
root lookup, offender ranking/dedup, budget round-trip, and the three
--check exit paths (pass, regression, missing budget) plus the new
--check --har combined write. Add requirements_test.txt case to the
should_run_import_time parametrized test.