bump glibc to 2.28

Summary: We no longer support Ubuntu (D13844)

Test Plan:
symbol-check.py is not working at the moment, so this is tested in D13970

Run contrib/devtools/test-symbol-check.py to detect any syntax error or anything else unexpected.

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D13973