Log Message:
py-packageurl: update to 0.17.1.

0.17.1 (2025-06-06)
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- Define "pkg" as a PackageURL ``SCHEME`` class attribute.
- Add support for Maven in ``purl2url``.

0.17.0 (2025-06-04)
-------------------

- Fix qualifiers type annotations.
- Fix parsing of names and namespaces with colons.