Unicode U+2007 character treated as whitespace on macOS

[frenchy64]

macOS Sequoia 15.2 (Intel)

This test for the keyword :<U+2007><U+2007> fails on macOS.

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/Users/ambrose/Projects/jank-local-dev/main/compiler+runtime/test/cpp/jank/read/lex.cpp:1664:
TEST SUITE: lex
TEST CASE:  UTF-8
  Whitespace Characters

/Users/ambrose/Projects/jank-local-dev/main/compiler+runtime/test/cpp/jank/read/lex.cpp:1778: ERROR: CHECK( tokens == make_tokens({ { 0, 7, token_kind::keyword, "  "sv } }) ) is NOT correct!
  values: CHECK( [ err(error(0 - 0, "invalid keyword: expected non-whitespace character after :")) ok(token(1, 3, symbol,  )) err(error(4 - 4, "expected whitespace before next token")) ok(token(4, 3, symbol,  )) ] == [ token(0, 7, keyword,   ) ] )

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[jeaye]

I've seen this showing up on some people's machine. I suspected it was a locale issue on that machine, not having UTF-8 setup properly.