Update sed command for compatibility with MacOS

[jorgecuesta]

Summary

It adapted the sed command in the prepare-dotenv.sh script to ensure compatibility with MacOS and Linux. Previously, the script only worked on Linux systems, but now it accounts for differences in the sed command on Unix-based systems.

Issue

The prepare-dotenv.sh shell script was using sed with the format just for Linux so anyone using OSx will get a silence error during yarn install

Type of change

Select one or more:

• New feature, functionality or library
• Bug fix
• Code health or cleanup
• Documentation
• Other (specify)

Testing

Documentation changes (only if making doc changes)

• make docusaurus_start; only needed if you make doc changes

Local Testing (only if making code changes)

• Unit Tests: make go_develop_and_test
• LocalNet E2E Tests: make test_e2e
• See quickstart guide for instructions

PR Testing (only if making code changes)

• DevNet E2E Tests: Add the devnet-test-e2e label to the PR.
  • THIS IS VERY EXPENSIVE, so only do it after all the reviews are complete.
  • Optionally run make trigger_ci if you want to re-trigger tests without any code changes
  • If tests fail, try re-running failed tests only using the GitHub UI as shown here

Sanity Checklist

• I have tested my changes using the available tooling
• I have commented my code
• I have performed a self-review of my own code; both comments & source code
• I create and reference any new tickets, if applicable
• I have left TODOs throughout the codebase, if applicable

[Olshansk]

@jorgecuesta In the future, create new branches in this repo (not your fork). You should have the proper permissions now.

[jorgecuesta]

Sure @Olshansk I will start working over this repo instead of mine. Thanks!