set version key explicitly

fontland/fontland/table/cff/cff-font.rkt

@@ -23,9 +23,6 @@ https://github.com/mbutterick/fontkit/blob/master/src/cff/CFFFont.js
           
       (for ([(k v) (in-hash (decode CFFTop stream))])
            (hash-set! cff-font k v))
-          
-      ;; because fontkit depends on overloading 'version key, and we don't
-      (hash-set! cff-font 'version (hash-ref cff-font 'x:version))
 
       (when (and (hash-has-key? cff-font 'version) (< (hash-ref cff-font 'version) 2))
         (match (hash-ref cff-font 'topDictIndex)

fontland/fontland/table/cff/cff-top.rkt

@@ -120,9 +120,7 @@ https://github.com/mbutterick/fontkit/blob/master/src/cff/CFFTop.js
 (define FDSelect
   (x:versioned-struct
    uint8
-   #:pre-encode
-   ;; because fontkit depends on overloading 'version key, and we don't
-   (λ (val) (dict-set val 'x:version (dict-ref val 'version)))
+   #:version-key 'version
    (dictify
     0 (dictify 'fds (x:array uint8 base-tproc))
     3 (dictify 'nRanges uint16be
@@ -205,9 +203,7 @@ https://github.com/mbutterick/fontkit/blob/master/src/cff/CFFTop.js
 
 (define CFFTop
   (x:versioned-struct
-   #:pre-encode
-   ;; because fontkit depends on overloading 'version key, and we don't
-   (λ (val) (hash-set! val 'x:version (hash-ref val 'version)) val)
+   #:version-key 'version
    fixed16be
    (dictify
     1 (dictify 'hdrSize uint8