There's a merged pull request on the void-packages repository

ART: update to 1.20, New package: mimalloc-2.1.2
https://github.com/void-linux/void-packages/pull/44503

Description:
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#### Testing the changes
- I tested the changes in this PR: **YES**

the mimalloc commit is taken from #37688, updated and fixed

cc @wangp 

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