Add conf-freeglut dependency to .opam

Co-authored-by: Jan Midtgaard <[email protected]>

Author: elias-utf8

packages/qcaml/qcaml.0.1.1/opam

@@ -33,6 +33,7 @@ depends: [
   "alcotest" {with-test}
   "odoc" {with-doc}
   "bisect_ppx" {with-test}
+  "conf-freeglut"
 ]
 build: [
   ["dune" "subst"] {dev}