Add C++ workflow file

[charlesbvll]

Issue

Description

No tests were made on the C++ SDK.

Related issues/PRs

N/A

Proposal

Explanation

Add tests for C++ to the CI.

Checklist

• Implement proposed change
• Make CI checks pass
• Ping maintainers on Slack (channel #contributions)

Any other comments?

N/A

[tanertopal]

@charlesbvll This PR might create a lot of cache eviction as we have a 10GB total limit for caches on GitHub actions.

See:

• https://github.com/adap/flower/actions/caches
• https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#managing-caches

I suggest using cache save only on the main branch and cache restore on the main and PR branches.

See:

• https://github.com/actions/cache/blob/main/save/README.md
• https://github.com/actions/cache/blob/main/restore/README.md

[charlesbvll]

@charlesbvll This PR might create a lot of cache eviction as we have a 10GB total limit for caches on GitHub actions.

See:

• https://github.com/adap/flower/actions/caches
• https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#managing-caches

I suggest using cache save only on the main branch and cache restore on the main and PR branches.

See:

• https://github.com/actions/cache/blob/main/save/README.md
• https://github.com/actions/cache/blob/main/restore/README.md

@tanertopal Thanks for the feedback! I updated the workflow file