pw_build: Install generated packages without --editable
pw_build: Install generated packages without --editable

Do not install generated packages with --editable so that they aren't
affected if the build directory is deleted.

Change-Id: I1128c85ecc131dfd41729de173ef7161c7534902
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/27820
Pigweed-Auto-Submit: Wyatt Hepler <cca3bedb37979eacd157a9bceb473582df8aea1e@google.com>
Commit-Queue: Auto-Submit <14637eda5603879df170705285bf30f5996692f0@pigweed.google.com.iam.gserviceaccount.com>
Reviewed-by: Armando Montanez <97ef6fdb231c129ac8827d9f0c4106bfbf57f74f@google.com>
Reviewed-by: Rob Mohr <d07614a8a0b466db08f68224f87d738b0f9615cf@google.com>

google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed