fonts: Allow deallocation and clear face cache.

So fonts can be reloaded when required. Fixes #6153.

renpy/text/font.py

@@ -761,6 +761,7 @@ def free_memory():
 
     scaled_image_fonts.clear()
     font_cache.clear()
+    face_cache.clear()
 
 
 def load_fonts():

renpy/text/ftfont.pyx

@@ -188,6 +188,10 @@ cdef class FTFace:
 
         public object fn
 
+    def __dealloc__(self):
+        if self.face != NULL:
+            FT_Done_Face(self.face)
+
     def __init__(self, f, index, fn):
 
         cdef int error

renpy/text/hbfont.pyx

@@ -369,6 +369,8 @@ cdef class HBFace:
         if self.mm_var:
             FT_Done_MM_Var(library, self.mm_var)
 
+        FT_Done_Face(self.face)
+
     def __init__(self, f, index, fn):
 
         cdef int error