The LavaMoat policy generation script would sporadically fail because
it ran the build concurrently three times, and the build includes
steps that delete the `dist` directory and write to it. So if one build
process tried to write to the directory after another deleted it, it
would fail.
This was solved by adding a new `--policy-only` flag to the build
script, and a new `scripts:prod` task. The `scripts:prod` task only
runs the script tasks for prod, rather than the entire build process.
The `--policy-only` flag stops the script tasks once the policy has
been written, and stops any other files from being written to disk.
This prevents the three concurrent build processes from getting in each
others way, and it dramatically speeds up the process.
This PR adds one LavaMoat background script policy or each build type. It also renames the build system policy directory from `node` to `build-system` to make its purpose more clear. Each build type has the original `policy-override.json` for `main` builds. The `.prettierignore` file has been updated to match the locations of the new auto-generated policy files.
We need to maintain separate policies for each build type because each type will produce different bundles with different internal and external modules.
Co-authored-by: Mark Stacey <markjstacey@gmail.com>
