Refactor GitHub Actions Workflows for Improved CI/CD Performance

[MartinMinkov]

Summary

This PR refactors the GitHub Actions workflows to improve the CI/CD pipeline performance for o1js by introducing parallel testing and optimized caching strategies.

All CI tests now take around 1h, down from around 3h, a 3x speed up!

Key Changes:

1. New Prepare Job:

   • Sets up the repository and Node.js environment.
   • Caches dependencies and build outputs (including all recursive git submodules).
   • Counts unit tests and calculates chunks for parallel execution.
   • Caches the entire repository for reuse.

2. Updated Build-And-Test-Server Job:

   • Restores repository and dependencies from cache.
   • Runs various integration tests and adds results to the job summary.

3. New Run-Unit-Tests Job:

   • Executes unit tests in parallel chunks
   • Uploads test results and adds them to the job summary.

4. Enhanced Build-And-Test-Web Job:

   • Caches Playwright browsers and runs end-to-end tests.
   • Uploads E2E test artifacts.

Benefits:

1. Faster Builds: Parallel test execution reduces overall testing time.
2. Efficient Caching: Speeds up jobs by reusing cached dependencies and repository states.
3. Enhanced Visibility: Detailed job summaries and artifact uploads provide better insights into test results.

Additional Work

• Each test completes at a different time, some being more computationally expensive. It would be great to spread these out over all chunks so we can avoid hot spots where there is an imbalance of easy/difficult tests for each chunk
• We could explore removing some proof tests or conditionally turn them on/off depending on changes

[shimkiv]

For some reason it still waits for status:

[shimkiv]

From PR description:

Enhanced Build-And-Test-Web Job:
...
Uploads E2E test artifacts.

Not a big deal, but I think it was always the case (uploading).