Rollup merge of #65321 - Mark-Simulacrum:remove-linker-no-utf8-test, r=nikomatsakis

Remove painful test that is not pulling its weight

Research suggests that we are not properly testing this case anyway, and
even if we were, it is unlikely that we will regress here -- or, perhaps
more accurately, if we do, I am uncertain that we care too much. It
definitely seems like an edge case, and one that is particularly
unlikely to occur as time goes on.

Fixes #63520

Author: tmandry