P2286R8_text_formatting_tuple fails on non-English locale

[AlexGuteniev]

FAIL: std :: tests/P2286R8_text_formatting_tuple:22 (1448 of 1578)
******************** TEST 'std :: tests/P2286R8_text_formatting_tuple:22' FAILED ********************
Build setup steps:
Build steps:
Build step failed unexpectedly.
Command: "C:\Program Files\Microsoft Visual Studio\2022\Preview\VC\Tools\MSVC\14.40.33807\bin\HostX64\x64\cl.EXE" "C:\Project\STL\tests\std\tests\P2286R8_text_formatting_tuple\test.cpp" "-IC:\Project\STL\out\x64\out\inc" "-IC:\Project\STL\llvm-project\libcxx\test\support" "-IC:\Project\STL\tests\std\include" "/nologo" "/Od" "/W4" "/w14061" "/w14242" "/w14265" "/w14582" "/w14583" "/w14587" "/w14588" "/w14749" "/w14841" "/w14842" "/w15038" "/w15214" "/w15215" "/w15216" "/w15217" "/w15262" "/sdl" "/WX" "/D_ENABLE_STL_INTERNAL_CHECK" "/bigobj" "/FIforce_include.hpp" "/w14365" "/w14668" "/w15267" "/D_ENFORCE_FACET_SPECIALIZATIONS=1" "/D_STL_CALL_ABORT_INSTEAD_OF_INVALID_PARAMETER" "/w14640" "/Zc:threadSafeInit-" "/EHsc" "/std:c++latest" "/MTd" "/permissive" "-fsanitize=address" "/Zi" "-FeC:\Project\STL\out\x64\tests\std\tests\P2286R8_text_formatting_tuple\Output\22\P2286R8_text_formatting_tuple.exe" "-link" "-LIBPATH:C:\Project\STL\out\x64\out\lib\amd64" "-LIBPATH:C:\Program Files\Microsoft Visual Studio\2022\Preview\VC\Tools\MSVC\14.40.33807\lib\x64" "/MANIFEST:EMBED" "/debug"
Exit Code: 2 (0x2)
Standard Output:
--
test.cpp
C:\Project\STL\tests\std\tests\P2286R8_text_formatting_tuple\test.cpp(161): error C2220: the following warning is treated as an error
C:\Project\STL\tests\std\tests\P2286R8_text_formatting_tuple\test.cpp(161): warning C4566: character represented by universal-character-name '\u00D6' cannot be represented in the current code page (1251)
C:\Project\STL\tests\std\tests\P2286R8_text_formatting_tuple\test.cpp(162): warning C4566: character represented by universal-character-name '\u00D6' cannot be represented in the current code page (1251)
--

[cpplearner]

#4631 fixes this