Fix macro conflict for USE_FREETYPE=1

[jeroen]

Basically backport of https://github.com/freetype/freetype/commit/5931268 / https://github.com/emscripten-ports/FreeType/commit/5931268eec

We want to avoid publicly exporting the TYPEOF macro which conflicts with other libraries. . IIUC the header here is the one that gets included in the compiler with -s USE_FREETYPE=1 ? This should fix https://github.com/emscripten-core/emscripten/issues/22571