Instead of using `kamal envify` to generate the .env file, we now assume
that it will be in place for us.
Options in place of `kamal envify`:
1. Pre-generate the .env file
2. Create the env file in the `.pre-init` hook
3. Log into a secret store/check you are logged in in the pre-init hook
Then use .dotenv command and variable substitution to interpolate the
secrets.
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