Rollup merge of #102195 - wesleywiser:copyright2, r=Mark-Simulacrum,joshtriplett

Improve the COPYRIGHT file

This is a cutdown version of #96784 which doesn't include the apfloat changes. At this point, the other 3 commits in this PR don't seem to be controversial and I'd like to go ahead and get those merged which will leave #96784 with only the more complex apfloat related change.

r? `@Mark-Simulacrum` since you are the reviewer on that PR

cc `@joshtriplett` since you also had feedback in that PR

Author: matthiaskrgr