Replace Sjeng with Arasan and add Stockfish for Mac

[AttackingOrDefending]

Type of pull request:

• Bug fix
• Feature
• Other

Description:

• Replaces Sjeng with Arasan for XBoard tests, as the Sjeng website is down. Also, Arasan is tested on both Windows and Linux.
• Adds Stockfish for Mac, so we also test Homemade engines in Mac.
• Tests buggy_engine in Mac

Related Issues:

The fact that the Sjeng website was down, was mentioned in #1035.

Checklist:

• I have read and followed the contribution guidelines.
• I have added necessary documentation (if applicable).
• The changes pass all existing tests.

Screenshots/logs (if applicable):

[MarkZH]

Is the Arasan engine cached by GitHub Actions?

[AttackingOrDefending]

Yes. All caches include the new engines.