These strings are allocated once and never changed, so they don't need
the additional overhead of a capacity given by String - instead, we can
use Box<str> and save on 16 bytes for each of these, *and* for each
Value since this is currently the largest Value variant.
Change-Id: I3e5cb070fe6c5bf82114c92d04f6bae775663a7e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10796
Autosubmit: aspen <root@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
5d72d3980f