Summary:
Upgrade tcmalloc and abseil to pull in fix for https://github.com/google/tcmalloc/issues/197.

This required removing some (unused) functions from gutil which are also defined in abseil, and fixing a test.
Jira: DB-15264

Original commit: 4d8b7b6aca1dd52558d35be18a260b684edd7942 / D41845

Test Plan: Existing tests

Reviewers: esheng

Reviewed By: esheng

Subscribers: ybase

Differential Revision: https://phorge.dev.yugabyte.com/D41889