Add test coverage for parse_qsl/parse_qs strict_parsing on malformed query fields

urllib.parse.parse_qsl() and parse_qs() accept a strict_parsing keyword that, when True, raises ValueError on a malformed query field — one without a = separator, e.g. "a=1&b&c=3". This error branch is currently not exercised by Lib/test/test_urlparse.py: the existing parse_qsl/parse_qs tests only cover well-formed inputs and the default lenient behavior, so a regression that silently dropped the strict_parsing check would not be caught. It would be good to add a small test covering the strict_parsing=True branch for both functions on str and bytes inputs, alongside a well-formed control. Addressed by PR #154207.

Linked PRs

• gh-154207

从 Lib/test/test_urlparse.py 开始，检查现有的 parse_qsl 和 parse_qs 测试，包括它们的 str 和 bytes 情况。确认 PR #154207 涵盖了 strict_parsing=True 对格式错误和格式正确的查询字段的处理，并使用相关的 urlparse 测试套件验证覆盖范围。