Update GitHub Actions

[64J0]

Description:

With this PR I'm:

• Updating the version of both the checkout and setup-dotnet actions used.
• Pin the environment version to avoid problems popping up in the future due to some release (avoiding latest tags whenever possible).
• Add a workaround for the MacOS dotnet tool restore, which was failing.

Let me know if there is anything you'd like to change in this PR.

Useful notes:

The MacOS workaround I found in this issue: https://github.com/actions/runner-images/issues/5768#issuecomment-1162684820. I added a new step to fix it when we're using MacOS as the host environment.

Other than this, one can find the actions mentioned before in the following links:

• checkout: https://github.com/actions/checkout
• setup-dotnet: https://github.com/actions/setup-dotnet

Finally, regarding the GitHub Actions host environment itself, one can find many details in this repository: https://github.com/actions/runner-images. It includes the possible versions, which tools are already installed there, etc.

[cartermp]

Wow, quite the issue involved. Thank you!