[SizzleUnrlsd]

Summary

Warnings Python raises while parsing an analysed source were printed on the analyzer's stderr. An invalid escape sequence, for example, is a SyntaxWarning from Python 3.12 and a DeprecationWarning on 3.11. With -j N each warning was printed twice, because the parent and a worker both parse every module.

parse_source is the single parsing entry point for both. It now ignores warnings inside warnings.catch_warnings(), so the warning filters of the rest of the process are left untouched.

Verification

New tests in tests/test_parse_warnings.py, red before the change:

• parsing raises no warning about the analysed source;
• parsing leaves the process's warning filters alone;
• --check with -j 1 and -j 2 prints nothing on stderr, with the expected report and exit status.

No existing test changed.

Results:

• Python 3.14.5: full suite green, apart from test_packaging.py::test_the_version_has_one_source_of_truth. That test also fails on main, because of locally installed metadata (0.8.0).
• Python 3.11.13: the new tests pass with the change. Without it, the two parsing tests fail with a DeprecationWarning.
• Linters: ruff check and mypy clean.
• Regression suite: not run. The change does not alter any analysis result.

Closes #241