freetype: Fix function signatures to match without casts Clang 16 has got a new stricter warning for casts of function types (see https://github.com/llvm/llvm-project/commit/1aad641c793090b4d036c03e737df2ebe2c32c57). This new warning gets included as part of the existing error diagnostic setting of -Wcast-function-type. This fixes errors like these: ../src/hb-ft.cc:1011:34: error: cast from 'void (*)(FT_Face)' (aka 'void (*)(FT_FaceRec_ *)') to 'FT_Generic_Finalizer' (aka 'void (*)(void *)') converts to incompatible function type [-Werror,-Wcast-function-type-strict] ft_face->generic.finalizer = (FT_Generic_Finalizer) hb_ft_face_finalize; ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~