From this thread: Can't install Plots on julia-1.6.0 - #14 by mkitti
It seems that that kind of error may be solved by emptying the LD_LIBRARY_PATH variable before running Julia:
% LD_LIBRARY_PATH=""
I just tested this in a pretty old machine (it runs the 3.10 kernel still), and Plots installed fine. Does that solves your issue?
(ps: that OS is Red Hat Enterprise Linux v7.2 - from 2014).