style: pipe operator for union type hints

[jhoward-lm]

This PR updates union type annotations to use the PEP-604 pipe operator, changing type hints like this:

Optional[Union[str, Dict[str, str]]]

to this:

str | dict[str, str] | None

The changes were auto-generated by running pyupgrade --py38-plus src/packageurl/__init__.py. It switches to using built-in types dict and tuple rather than typing.Dict and typing.Tuple.

Miscellaneous

• applied refactorings suggested by sourcery
  • assign-if-exp: replace if statements, e.g.:

     if isinstance(s, str):
         s_bytes = s.encode("utf-8")
     else:
         s_bytes = s

    with if expressions:

    s_bytes = s.encode("utf-8") if isinstance(s, str) else s

  • avoid-builtin-shadow: don't assign to builtin variable type (renames local variable type to type_ in PackageURL.from_string())
• applied fixes suggested by ruff
  • RUF010: Use explicit conversion flag (change instances of f"{repr(value)}" to f"{value!r}")

[jhoward-lm]

@tdruez @gruebel Here's the follow-on PR for what we discussed in this comment