Remove inline comment clutter from LinkableElementSet

There are some comments that are a bit outdated and confusing,
or at the very least not terribly useful, in the first sections of
the LinkableElementSet, so we remove them. This was found in a
modification to the LinkableDimension class, as the longer comment
makes a reference to it.

metricflow/model/semantics/linkable_element_set.py

@@ -21,17 +21,6 @@ class LinkableElementSet:
     TODO: There are similarities with LinkableSpecSet - consider consolidation.
     """
 
-    # Dictionaries that map the path key to context on the dimension
-    #
-    # For example:
-    # {
-    #   "listing__country_latest": (
-    #     LinkableDimension(
-    #       element_name="country_latest",
-    #       entity_links=("listing",),
-    #       semantic_model_origin="listings_latest_source",
-    #   )
-    # }
     path_key_to_linkable_dimensions: Dict[ElementPathKey, Tuple[LinkableDimension, ...]] = field(default_factory=dict)
     path_key_to_linkable_entities: Dict[ElementPathKey, Tuple[LinkableEntity, ...]] = field(default_factory=dict)
     path_key_to_linkable_metrics: Dict[ElementPathKey, Tuple[LinkableMetric, ...]] = field(default_factory=dict)
@@ -54,7 +43,6 @@ def merge_by_path_key(linkable_element_sets: Sequence[LinkableElementSet]) -> Li
             for path_key, linkable_metrics in linkable_element_set.path_key_to_linkable_metrics.items():
                 key_to_linkable_metrics[path_key].extend(linkable_metrics)
 
-        # Convert the dictionaries to use tuples instead of lists.
         return LinkableElementSet(
             path_key_to_linkable_dimensions={
                 path_key: tuple(dimensions) for path_key, dimensions in key_to_linkable_dimensions.items()