gh-103204: `http.server` - Enforce that HTTP version numbers must consist only of digits (#103205)

Reject HTTP requests with invalid http/x.y version numbers: x or y being non-digits or too-long.

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Co-authored-by: Oleg Iarygin <oleg@arhadthedev.net>
Co-authored-by: Gregory P. Smith <greg@krypto.org>