refactor(tvix/rm): introduce helper for AttrSet Entry API r/4443

There are multiple points where an insertion needs to be done into an
attribute set, but copying the key or checking for presence before
insertion should be avoided

As that is a little bit noisy, it's been factored out into a helper
function in this commit.

Change-Id: Ibcb054ebeb25a1236c06c812f47c8e74180d4fc9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6107
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>

0 files changed, 0 insertions, 0 deletions