Accept Unicode str values in parse_options_header

[gyanu2507]

parse_options_header already takes str | bytes | None, but a str with characters outside Latin-1 raises UnicodeEncodeError. That's the filename case people actually hit:

parse_options_header('form-data; name="upload"; filename="中文.doc"')

Bytes (the WSGI path) were already fine. For str this encodes as Latin-1 when it fits and falls back to UTF-8 otherwise, so the public API matches its type hint.

The issue asked which of the three options you wanted. I went with supporting Unicode str rather than a clearer error, because the signature already accepts str and that's what callers pass for filenames. Happy to switch to a dedicated error if you'd rather keep the Latin-1-only contract explicit.

Fixes#319

[codspeed-hq]

Merging this PR will not alter performance

✅ 5 untouched benchmarks
⏩ 5 skipped benchmarks¹

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_{Comparing gyanu2507:fix/parse-options-header-unicode (4b35e58) with main (d9cb4c6)}

Footnotes

1. 5 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[cubic-dev-ai]

No issues found across 3 files

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