fix(julia): add callback for do_clause

the do_clause is a multiline anonymous function which gets passed as the
first argument of another function. it's basically like a
function_definition, except you don't give it a name

Author: rokke-git

queries/julia/context.scm

@@ -12,3 +12,5 @@
   condition: (_) @context.final) @context
 
 (try_statement) @context
+
+(do_clause) @context