CHIA-3718 Handle building chiavdf for MacOS when CMake is already installed

[AmineKhaldi]

Purpose:

Addresses https://github.com/Chia-Network/chia-blockchain/actions/runs/17383374050/job/49377026478#step:13:47

Current Behavior:

New Behavior:

Testing Notes:

[arvidn]

I assume install-timelord.sh is meant to work on end-user's machines as well. Where cmake may not already be installed

[AmineKhaldi]

I assume install-timelord.sh is meant to work on end-user's machines as well. Where cmake may not already be installed

We now check if CMake exists, and if not, we install it.

[arvidn]

this looks good to me. I'd like someone else to review it as well though

[coveralls-official]

Pull Request Test Coverage Report for Build 17401543637

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 56 unchanged lines in 6 files lost coverage.
• Overall coverage decreased (-0.04%) to 91.269%

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Files with Coverage Reduction	New Missed Lines	%
chia/wallet/wallet_node.py	2	87.56%
chia/full_node/weight_proof.py	4	90.6%
chia/full_node/full_node_api.py	6	86.07%
chia/full_node/full_node.py	9	87.56%
chia/server/node_discovery.py	10	80.5%
chia/_tests/core/util/test_lockfile.py	25	77.31%

Totals
Change from base Build 17309077769:	-0.04%
Covered Lines:	102699
Relevant Lines:	112391

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💛 - Coveralls