Only return unique names

Author: radarhere

src/PIL/ImageFont.py

@@ -675,8 +675,12 @@ def get_variation_names(self) -> list[bytes]:
         :returns: A list of the named styles in a variation font.
         :exception OSError: If the font is not a variation font.
         """
-        names = self.font.getvarnames()
-        return [name.replace(b"\x00", b"") for name in names]
+        names = []
+        for name in self.font.getvarnames():
+            name = name.replace(b"\x00", b"")
+            if name not in names:
+                names.append(name)
+        return names
 
     def set_variation_by_name(self, name: str | bytes) -> None:
         """