Define *print-meta* as a bindable dynamic var

clojure.core/*print-meta* was missing, so (binding [*print-meta* true] …) failed
to compile ("var of non-var"). Add it (default false, like the JVM); corpus
covers binding it.

host/chez/dynamic-var-defaults.ss

@@ -25,3 +25,6 @@
 
 ;; *print-readably* — bound by pr-family / with-out-str-style code; default true.
 (def-var! "clojure.core" "*print-readably*" #t)
+
+;; *print-meta* — when true, pr prints metadata with a ^ prefix; default false.
+(def-var! "clojure.core" "*print-meta*" #f)

test/chez/corpus.edn

@@ -2650,6 +2650,7 @@
   {:suite "reader / auto-resolved keywords" :label "::kw resolves to the current ns" :expected "true" :actual "(= ::a ::a)"}
   {:suite "clojure.edn / reader opts" :label ":default receives the tag as a symbol" :expected "[true \"foo\" 5]" :actual "(do (require (quote [clojure.edn :as edn])) (let [r (edn/read-string {:default (fn [t v] [t v])} \"#foo 5\")] [(symbol? (first r)) (name (first r)) (second r)]))"}
   {:suite "metadata / lazy seqs carry meta" :label "with-meta on a lazy seq" :expected "{:k 1}" :actual "(meta (with-meta (map inc [1 2 3]) {:k 1}))"}
+  {:suite "dynamic vars / *print-meta*" :label "*print-meta* is a bindable dynamic var" :expected "true" :actual "(binding [*print-meta* true] (true? *print-meta*))"}
   {:suite "conformance / CRITICAL: lazy sequences" :label "self-ref lazy-cat fib" :expected "[0 1 1 2 3 5 8 13 21 34]" :actual "(do (def fib-seq (lazy-cat [0 1] (map + (rest fib-seq) fib-seq))) (take 10 fib-seq))"}
   {:suite "conformance / CRITICAL: multi-collection map" :label "map two colls" :expected "[11 22 33]" :actual "(map + [1 2 3] [10 20 30])"}
   {:suite "conformance / CRITICAL: multi-collection map" :label "map three colls" :expected "[12 24 36]" :actual "(map + [1 2 3] [10 20 30] [1 2 3])"}