Make confusable character warning less jarring (#25069)

Make confusable character warning less jarring (#25069)

This commit assumes that the warning can be made more discreet
so as to make it less annoying for the people that do not actually
need the warning, without necessarily increasing the risk for those
that do need it.

This doesn't fix the underlying problem of the warning being shown
in certain cases that, say, a certain kind of whitespace character
like 0x1E could be absolutely justifiable from a technical
perspective.

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Co-authored-by: delvh <dev.lh@web.de>