data_to_ports max_depth default to 0

Makes it more compatible with LazyLibrary -- with recursive approach, we
have to load all the subcells to run ports2data, but those subcells may
or may not exist (e.g. partial library, or maybe we've removed some
duplicates-to-be prior to merging with a different lib)

masque/utils/ports2data.py

@@ -57,8 +57,9 @@ def data_to_ports(
                                         # LazyLibrary protects against library[ref.target] causing a circular lookup.
                                         # For others, maybe check for cycles up front? TODO
         name: Optional[str] = None,     # Note: name optional, but arg order different from read(postprocess=)
-        max_depth: int = 999_999,
+        max_depth: int = 0,
         skip_subcells: bool = True,
+        # TODO missing ok?
         ) -> Pattern:
     """
     # TODO fixup documentation in port_utils