[CLN] remove dead code in metadata proto conversion (#2083)

## Description of changes

*Summarize the changes made by this PR.*
 - Improvements & Bug fixes
- This code case can never happen because the direct equality case is
handled already.
           this removes dead code and comments the logic
 - New functionality
	 - ...

## Test plan
*How are these changes tested?*

- [ ] Tests pass locally with `pytest` for python, `yarn test` for js,
`cargo test` for rust

## Documentation Changes
*Are all docstrings for user-facing APIs updated if required? Do we need
to make documentation changes in the [docs
repository](https://github.com/chroma-core/docs)?*

chromadb/segment/impl/metadata/grpc_segment.py

@@ -247,23 +247,9 @@ def _where_to_proto(self, where: Optional[Where]) -> pb.Where:
                                 f"Expected where operand value to be a string, int, or float, got {operand}"
                             )
                     else:
-                        # Our key is a metadata field name and the value is meant
-                        # to be compared for strict equality.
-                        if type(operand) is str:
-                            ssc = pb.SingleStringComparison()
-                            ssc.value = operand
-                            ssc.comparator = pb.GenericComparator.EQ
-                            dc.single_string_operand.CopyFrom(ssc)
-                        elif type(operand) is int:
-                            sic = pb.SingleIntComparison()
-                            sic.value = operand
-                            sic.generic_comparator = pb.GenericComparator.EQ
-                            dc.single_int_operand.CopyFrom(sic)
-                        elif type(operand) is float:
-                            sfc = pb.SingleDoubleComparison()
-                            sfc.value = operand
-                            sfc.generic_comparator = pb.GenericComparator.EQ
-                            dc.single_double_operand.CopyFrom(sfc)
+                        # This case should never happen, as we've already
+                        # handled the case for direct comparisons.
+                        pass
 
             response.direct_comparison.CopyFrom(dc)
         return response