Fix dict_to_pairs Julia template and redact credentials in pretty printer

Julia dict_to_pairs now produces Vector{Tuple} instead of Vector{Pair}.
Credentials are redacted from pretty-printed output for security.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: vustef

meta/src/meta/codegen_templates.py

@@ -135,7 +135,7 @@ class BuiltinTemplate:
     "make_empty_bytes": BuiltinTemplate("UInt8[]"),
     "dict_from_list": BuiltinTemplate("Dict({0})"),
     "dict_get": BuiltinTemplate("get({0}, {1}, nothing)"),
-    "dict_to_pairs": BuiltinTemplate("sort(collect(pairs({0})))"),
+    "dict_to_pairs": BuiltinTemplate("sort([(k, v) for (k, v) in {0}])"),
     "has_proto_field": BuiltinTemplate("_has_proto_field({0}, Symbol({1}))"),
     "string_to_upper": BuiltinTemplate("uppercase({0})"),
     "string_in_list": BuiltinTemplate("({0} in {1})"),

meta/src/meta/grammar.y

@@ -1066,7 +1066,7 @@ iceberg_config
         $3: String = $$.catalog_uri
         $4: Optional[String] = $$.scope if $$.scope != "" else None
         $5: Optional[Sequence[Tuple[String, String]]] = builtin.dict_to_pairs($$.properties) if not builtin.is_empty(builtin.dict_to_pairs($$.properties)) else None
-        $6: Optional[Sequence[Tuple[String, String]]] = builtin.dict_to_pairs($$.credentials) if not builtin.is_empty(builtin.dict_to_pairs($$.credentials)) else None
+        $6: Optional[Sequence[Tuple[String, String]]] = builtin.none()
 
 iceberg_config_scope
     : "(" "scope" STRING ")"