Summary:
A couple places in code have dangling references in the form of:
```
  const auto& variable = function_that_returns_value();
```
These were caught by the `-Wdangling-references` warning in newer versions of GCC (than we normally build with).

This change removes the references.
Jira: DB-18255

Test Plan: Jenkins

Reviewers: asrivastava

Reviewed By: asrivastava

Subscribers: ybase, yql

Differential Revision: https://phorge.dev.yugabyte.com/D46646