Separate generation of environment scripts/JSON files from the object
that stores that environment.
Change-Id: I4dba68636d79d23bc50ec737753b115ed81e26d5
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/33000
Reviewed-by: Keir Mierle <keir@google.com>
Commit-Queue: Rob Mohr <mohrr@google.com>