Fix freetype name mangling typo
Code extracted from:
https://gitlab.kitware.com/third-party/freetype.git
at commit 7b58b28e2e35c6e40fc22635904e7616edf805e0 (for/vtk-20220304-2.11.0).
Update freetype to fix typo in the freetype name mangling header; issue #18478 (closed)
The typo causes conflicts when linking static VTK builds with other libraries also using freetype. The following:
#define vtkfreetype_FT_MulFix vtkfreetype_vtkfreetype_FT_MulFix
needs to change to:
#define FT_MulFix vtkfreetype_FT_MulFix