Allow #push-options "--lax"

Author: gebner

src/basic/FStarC.Options.fst

@@ -1761,6 +1761,7 @@ let settable = function
     | "ide_id_info_off"
     | "keep_query_captions"
     | "lang_extensions"
+    | "lax"
     | "load"
     | "load_cmxs"
     | "log_queries"

tests/tactics/Admit.fst

@@ -2,7 +2,7 @@ module Admit
 
 open FStar.Tactics.V2
 
-#push-options "--admit_smt_queries true"
+#push-options "--lax"
 let test () : squash False =
   _ by (
     ()