release: remove llvm unit tests

[luoliwoshang]

parts of #12

refer the https://github.com/Homebrew/homebrew-core/blob/5488de13fc37a10e609a49b087601f227ae29039/Formula/l/llvm%4019.rb#L128

https://llvm.org/docs/CMake.html

LLVM_INCLUDE_TESTS:BOOL
Generate build targets for the LLVM unit tests. Defaults to ON. You can use this option to disable the generation of build targets for the LLVM unit tests.

before will

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current

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