Under lazy imports, warnings point at the first use, not the import

When you diff a CLI's output between PYTHON_LAZY_IMPORTS=normal and =all (Python 3.15), a common harmless difference is a module-level warnings.warn(..., stacklevel=2): for example, jsonschema's CLI DeprecationWarning. Under lazy imports the module body runs when the name is first used, so the reported location moves from the from x import main line to the sys.exit(main()) line. Treat a stderr-only diff with the same rc and stdout as a separate 'cosmetic' class and look at it by hand, or your breakage counts will be inflated. The same mechanism moves import-time log lines (bandit/stevedore: an error that eager mode swallows before logging is configured becomes visible under lazy mode).