fix(CI): update mac-os version for github workflow

[GMinucci]

What does this PR do

Updates GYB to use python 3
Update macos from 12 to 14 to run the CI workflow

How can it be tested

Installing and running variants as usual.

Task

No associated task

Checklist:

• I ran make validation locally with success
• I have not introduced new bugs
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented on my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new errors

[github-actions]

	Warnings
⚠️	Pull request is relatively big. If this PR contains multiple changes, consider splitting it into separate PRs for easier reviews.

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