Update macos ci

[otaj]

What does this PR do?

GH is deprecating MacOS 10.15

actions/runner-images#5583

Does your PR introduce any breaking changes? If yes, please list them.

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• Did you list all the breaking changes introduced by this pull request?
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PR review

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Did you have fun?

Make sure you had fun coding 🙃

cc @Borda @tchaton @rohitgr7 @carmocca @akihironitta