[ci] Cleanup forked build files
Unforks these scripts now that we are fully migrated to GH. ghstack-source-id: e1e15452f2d2e178a5b56203ebd0b42151e6a9ba Pull Request resolved: https://github.com/facebook/react/pull/30506
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Lauren Tan committed
70885cfebec3adf4ff89f639f38302c57eda12ce
Parent: 6b82f3c