Bump Python requirement fontTools to 4.39.2

requirements.txt

 arkindex-client==1.0.11
 boto3==1.26.95
 editdistance==0.6.2
-fontTools==4.38.0
+fontTools==4.39.2
 imageio==2.26.1
 mlflow==2.2.2
 networkx==3.0